Putting Soil Health First
A Climate-Smart Idea for Ontario
November 2016
Table of Contents
Executive Summary .................................................................................................................................... 4
The Two Stories of Modern Agriculture ........................................................................................................ 6
Story 1 – Feeding the World .................................................................................................................... 6
Story 2 – But at What Cost? .................................................................................................................... 7
GHG emissions ................................................................................................................................... 7
Food security and ecological resilience................................................................................................. 8
Other impacts: water, pesticides, etc. ................................................................................................ 10
Time to Change Course ........................................................................................................................ 10
Putting Soil Health First ............................................................................................................................. 12
What is Soil Health? .............................................................................................................................. 12
The complex, busy world beneath our feet ......................................................................................... 12
The substantial benefits of healthy soils .................................................................................................. 13
Bacteria and Fungi: The Soil’s Structural Engineers ............................................................................. 14
The Original Carbon Trading Scheme .................................................................................................... 15
How plants get their nutrition .............................................................................................................. 15
Nutrient sources ................................................................................................................................ 16
Faster nutrient delivery ....................................................................................................................... 16
Carbon trading and sequestration ...................................................................................................... 17
The Soil Health Approach – Principles and Practices .............................................................................. 17
Principles .......................................................................................................................................... 18
Throwing Sand in the Gears: How the Inappropriate or Over Use of Synthetic Inputs Can Impair the
Natural System .................................................................................................................................. 19
Best Management Practices .............................................................................................................. 19
Champions of Soil Health.......................................................................................................................... 22
U.S. Soil Health Champions .................................................................................................................. 22
Brown Ranch, North Dakota .............................................................................................................. 22
Klaas and Mary-Howell Martens, organic farmers, New York State ...................................................... 23
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
Ontario Soil Health Champions .............................................................................................................. 24
The Belan family farm, near Inwood, Ontario. ...................................................................................... 24
The Rogers farm, Lambton Shores, Ontario ........................................................................................ 26
Realizing the Promise of Soil Health ........................................................................................................... 28
A Role for Research .............................................................................................................................. 28
What are Other Jurisdictions Doing? ...................................................................................................... 29
United States .................................................................................................................................... 29
France .............................................................................................................................................. 30
The Climate Adaptation and Mitigation Potential of Soil Health for Ontario ................................................ 30
Adaptation ........................................................................................................................................ 30
Mitigation .......................................................................................................................................... 31
From Champions to a New Normal ........................................................................................................ 34
An Important Role for the OMAFRA ........................................................................................................ 35
The Potential of Carbon Offsets in Agriculture ......................................................................................... 37
ECO Comment and Recommendations .................................................................................................... 38
Comment ............................................................................................................................................. 38
Recommendations ................................................................................................................................ 39
Endnotes ................................................................................................................................................. 40
PUTTING SOIL HEALTH FIRST
3
Executive Summary
Modern agriculture has achieved great success in feeding the world. Over the past few decades, yields have
consistently risen as prices, on a relative basis, have dropped. New technologies and inputs have made
growing crops simpler and more cost-effective. The environmental price of all this advancement, however,
includes greater greenhouse gas emissions, nutrient pollution of water bodies such as Lake Erie, and
increased soil degradation and erosion. Now, climate change is bringing these concerns into sharper focus,
as they threaten basic food security in Ontario.
Fortunately, an exciting opportunity now exists to both continue
to feed ourselves cost-effectively and to also protect the natural
world, by building soil ecosystems and soil organic matter. This
emerging opportunity is known as the soil health approach.
Yields have continually
gone up while the price
of food has, in relative
terms, come down.
The concept of “soil health” begins with the acknowledgement
that soils are living ecosystems. A handful of healthy soil contains more living organisms than there are people
on the planet. These organisms, which include bacteria, fungi, protozoa, and nematodes, as well as slightly
larger, visible creatures such as mites and earthworms, together make up the soil food web. These organisms
are responsible for a myriad of beneficial functions, including soil fertility, good soil structure, water quality,
toxics reduction, disease suppression, and carbon sequestration. The latter is increasingly viewed as an
important method for mitigating climate change.
Unfortunately, conventional agriculture has all but ignored the soil food web. It has replaced its functions in part
or in whole with synthetic inputs, such as fertilizer and pesticides. Even more importantly, it has utilized
management practices, such as frequent tillage and leaving fields bare between crops, that deplete the soil
food web. As a result, soil structure has suffered, leading to soil degradation and erosion. In addition, the
continued over-use of synthetic inputs has led to pollution and an even further reduction in the number of soil
organisms, as many pesticides are also toxic to the beneficial forms of soil life.
The soil health approach takes a completely different focus: first and foremost, it aims to protect and enhance
soil life. This focus is crystallized in the following basic principles:
•
•
•
•
•
Keep the soil covered, with plants or plant residues, at all times;
Maximize the diversity of crops;
Minimize soil disturbance;
Keep live roots in the ground all year; and,
Use organic inputs wherever possible.
Farmers who adopt the soil health approach use management practices rooted in these principles. These
practices include: no-till or various types of conservation tillage; planting cover crops (crops planted to improve
soil, rather than to harvest for market); using complex crop rotations; the “4Rs” of synthetic fertilizer use (“right
source, right rate, right time, and right place”); producing and using compost; the integration of livestock with
cropping systems; and the employment of ecological grazing systems.
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
Farmers who have adopted and systematically applied the principles and practices outlined above have been
able to gradually but dramatically reduce synthetic inputs while at the same time becoming much more
profitable. For example, Gabe Brown, a long-time soil health practitioner in North Dakota, has been able to
increase his yields, improve his soil, and boost his profits – all while eliminating fertilizer inputs and reducing his
pesticide use to one herbicide application every two to three years. Here in Ontario, the Belan family farm has
been practicing no-till farming for 25 years and have recently introduced cover crops as well. They also have
reduced their costs without lowering yields, boosting their profitability. At the same time, they have significantly
reduced their environmental footprint; in fact, the Belans have increased the carbon levels in their soils by three
per cent, which means that they have sequestered about 48,000 tonnes of CO2 since changing their soil
management methods.
This is all very good news. By putting soil health first, it seems likely that farmers can build on agriculture’s
amazingly successful modern history; they can address head-on the environmental shadow that has always
been nagging at the edges of the accomplishments. It won’t be easy, however. Conventional agriculture has
worked very well from the perspective of the individual farmer, in part because its practices are relatively simple
to execute. In contrast, a soil health approach requires greater effort by growers in terms of planning,
monitoring, and managing complex rotations that often include cover or secondary crops with no obvious
markets. Effectively managing disease and pest issues are another major challenge when shifting to a new
approach.
Accordingly, building a wide-scale soil health focus in Ontario agriculture cannot be done overnight. Many
farmers are understandably skeptical about moving away from a system that has been so successful for them
and their families. They need solid evidence and successful role models to help guide the shift, along with
appropriate support for financial risk as they experiment with these new ideas. The Ontario government, and
especially the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), has an extremely important
role to play in making all of this happen. The ministry should make the soil-health ‘entrance ramp’ for farmers
as wide, accessible, and low-risk as possible.
To this end, the ECO is offering the following recommendations.
•
•
•
•
The province of Ontario should become a signatory of the 4/1000 Initiative, a climate-smart soil health
commitment program championed by the Government of France.
The OMAFRA should:
o co-ordinate the development of a protocol, with supporting methods and technologies, for
reliably estimating soil-carbon levels in Ontario; and
o implement a program for estimating soil-carbon levels across the province every three years,
and making these results public.
The Ontario government should find a way to link the cost of crop insurance to soil-carbon levels, in
recognition of the fact that, over time, high-carbon soils reduce risks to crops.
The province should develop a program to provide financial support for up to 10 years for farmers who
adopt soil health best management practices, designed to offset any yield loss due to transition
issues.
PUTTING SOIL HEALTH FIRST
5
The Two Stories of Modern Agriculture
Story 1 – Feeding the World
Agriculture has had a marvellous run over the past century. A modern success story, it began its most rapid
ascent just after World War I, with the introduction and subsequent rapid adoption of nitrogen-based synthetic
fertilizers.1 It continued to expand through the “green revolution” of the post-WW II decades, when high-yield
crop varieties were developed and deployed in conjunction with improved water-management systems, more
effective pesticides, and bigger and better farm equipment. Genetically modified crops, with attributes such as
herbicide (glyphosate) resistance and built-in pesticides (Bt), appeared in the 1990s2 and have made growing
common field crops, such as corn and soybeans, much simpler and less expensive. Most recently, modern
technology, such as GPS-guided tractors, variable-rate fertilizer spreaders, yield-monitoring harvesters, and
field-surveillance drones, are already delivering on the promise of more cost-effective, reduced-input,
“precision” agriculture.
The results of all this innovation have been remarkable.
Yields have continually gone up while the price of food has,
in relative terms, come down.3,4 For instance, over the past
30 years, average grain corn yields in Ontario have risen
from 1025 bushels per acre to 170,6 winter wheat yields
have climbed from 677 bushels per acre to 78,8 and
soybean yields have increased from 379 bushels per acre
to 46.10 In terms of price, food took up almost 19 per cent
of household income in Canada in 1969; forty years later,
that share had dropped to slightly over 10 per cent, while
Figure 1: Grain corn yields in Ontario 1984-2014
offering consumers a greater variety of food options than
ever before.
Savings have come from all of the factors mentioned above, but also from changes in the way farms are run.
They have gotten bigger and more intensive in design and operation, a change largely driven by economies of
scale.11 Although in Ontario most farms are still family-operated, many of the elements of large-scale, intensive
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
farming, common in other parts of the developed world, are
also employed here. These include: simplified crop rotations
(with few forages included);i control of pests and weeds
primarily by means of insecticides, fungicides, and herbicides;
leaving soils bare between crops; and frequent and aggressive
tillage. Human management is often supplemented, or even
replaced, with highly engineered inputs and “smart” equipment.
No amount of chemical
input can mitigate the
impacts of insufficient
water at key points in crop
development.
A recent increase in interest by Ontario farmers in beneficial management practices such as cover crops and
conservation tillage suggests that the province may be on the verge of a transition to a lower-input model. The
case studies on pp. 22-27 lend support to this position. However, the area of Ontario farmland under these
better management practices is still relatively small, and the high-input, intensive model, commonly referred to
worldwide as conventional agriculture, appears to still be the norm in our province.
Story 2 – But at What Cost?
This highly successful and constantly evolving model of agriculture has always had its doubters and
detractors, especially with regard to its impact on the environment. Over the past few years, climate change
has brought these concerns into sharper focus in three categories: greenhouse gas (GHG) emissions;
adaptation/food security; and other environmental impacts.
GHG emissions
According to Canada’s official national inventory,12 agriculture in
Ontario is responsible for about 10.0 megatonnes (Mt) of GHGs
per year,ii or about 5.9 per cent of the province’s total emissions
(see Figure 1). Almost half of those emissions (4.3 Mt) result from
the direct application of fertilizer to soils: nitrogen fertilizers
generate nitrous oxide (N2O) emissions (3.7 Mt of CO2e), while
manures (0.6 Mt CO2e) give off methane (CH4). Of the remaining
5.7 Mt CO2e, almost two-thirds (3.6 Mt CO2e) are due to CH4
generated by the digestive systems of ruminants, such as cattle,
(known as enteric fermentation) and most of the remainder (1.9 Mt
CO2e) are due to CH4 from manure storage operations.
Wilting leaves show drought stress on corn
Source: Ministry of Agriculture, Food and Rural
Affairs.
A reduction in the number of livestock in the province over the past few years has resulted in the almost
complete elimination of forages in crop rotations.
i
ii
The units used for GHGs are called carbon dioxide equivalents (CO2e), where CO2 is used as the standard.
PUTTING SOIL HEALTH FIRST
7
A new approach is
required, one that
is sufficient to
solve the many
environmental
problems outlined
here…without
foregoing the
productivity and
profitability of
modern
agriculture.
Figure 2: Agriculture’s Contributions to Ontario’s GHG Emissions
Another 3.2 Mt CO2e of greenhouse gas emissions arise as a result of the loss of soil organic matter (SOM)
from agricultural land. These emissions, which are comprised of CO2 (2.7 Mt of CO2e), and N2O (0.5 Mt of
CO2e) result from management practices, such as aggressive tillage and summer fallow (i.e., “resting” a field
for a planting season), which tend to reduce SOM levels.13 Agriculture and Agri-Food Canada (AAFC)
estimates that 82 per cent of Ontario farmland is losing SOM annually, with over 50 per cent of that land losing
at least 90 kg of CO2e per hectare per year.14
Note that these emissions are classified under the Land Use, Land Use Change and Forestry (LULUCF)
sector, rather than the agricultural sector, of the National Inventory Report,15 and are therefore not included in
the latter’s 10 Mt CO2e contribution. Nor are they included in Ontario’s official emissions for the purpose of
meeting national emission-reduction targets; however, they are tracked and recorded in Canada’s National
Inventory Reports.iii
The reductions in soil carbon represented by these figures can be considered as both an important loss and a
major opportunity and will be discussed in significant detail in the pages that follow.
Food security and ecological resilience
The term “food security” refers to a situation where people have physical, social and economic access to
sufficient safe and nutritious food.16 The ability of any jurisdiction, such as Ontario, to produce enough to feed
iii
See Chapter 3 of the ECO’s 2016 GHG Report, entitled Facing Climate Change.
8
ENVIRONMENTAL COMMISSIONER OF ONTARIO
its own population is dependent on a variety of physical, economic, and social factors. One very important
physical factor is ecological resilience, which is the ability of a system (in this case our agricultural lands) to
tolerate disturbances without changing to a different, less productive, state (i.e., collapsing) and/or to recover
from such disruptions in a reasonable period of time.17
In a changing climate, resilience is extremely important. Resilient agricultural systems could allow Ontario to
maintain, or even exceed, current levels of agricultural productivity in the face of significant change.18,19
Temperatures in Ontario will not only be higher on average, but will hit extreme levels (i.e., above 30 o C) more
often and for longer periods of time. High daily maximum temperatures are very dangerous, as yields for crops
like corn and soybeans drop precipitously with the number of days (and even more so, nights) above 30o C.20
Another significant threat to agricultural yields is the potential lack of timely availability of moisture. No amount
of chemical input can mitigate the impacts of insufficient water at key points in crop development. Climate
change is expected to create much more variability with longer periods of drought mixed with extreme
precipitation events. This is potentially devastating to crop yields.21, 22
As will be discussed in some detail below, Ontario’s ability to cope
with drought and heat, mixed with extreme storms, depends heavily
on the health of our topsoil. This makes it particularly dangerous that
soil-carbon levels are dropping on more than 80 per cent of Ontario
farms. Soil organic matter is essential to the ability of the soil to allow
the rapid infiltration of rain water, to better retain its structure under
intense rainfall, and to resist erosion.23, 24 Therefore, it is not surprising
that Ontario farms are also subject to an increasing risk of erosion (see
“Soil: Ontario’s Eroding Asset” in the ECO’s 2008/2009 Annual
Report). The resulting sedimentation of lakes and rivers is the mirror
problem to the loss of productive topsoil, and both are related to the
declining levels of organic matter on Ontario farms.
Algae bloom in Lake St. Clair, July 28,
2015.
Source: Landsat imagery courtesy of NASA
Goddard Space Flight Centre and U.S.
Geological Survey
Another closely related concern is the potential for crop loss due to flooding. Soils low in organic matter
cannot absorb rainfall quickly enough to prevent the rapid run-off of surface water. This can result in heavy
flooding of lower-lying fields, especially during the kinds of extreme weather expected with climate change.25
In addition, as average temperatures rise and the growing season lengthens, many new plant species,
including invasive weed species and herbicide-resistant weeds, will find Ontario’s climate to their liking.26
Together, these climate-related factors pose a significant threat to Ontario’s agriculture sector, raising issues of
negative impacts on both the province’s economy and its food security.
PUTTING SOIL HEALTH FIRST
9
Other impacts: water, pesticides, etc.
Impaired water quality, primarily in Lake Erie but to a lesser degree in surface waters generally, has been the
environmental issue receiving the most attention in recent years. Algal blooms are the visual trademark of this
problem, which is known as eutrophication.27 Phosphorus run-off from agricultural fields in Ontario, and to an
even greater extent several northern American states, is one of the causes of this problem. The ECO wrote
about phosphorus in our 2012/2013 Annual Report (“From Peak P to P Soup: The Phosphorus Challenge on
Ontario Farms”), recommending that the Ministry of Agriculture, Food and Rural Affairs (OMAFRA) place more
emphasis on soil health and less on after-the-fact solutions, such as physical barriers to P run-off.
Eutrophication is both a hazard to human health and a threat to biodiversity.
Other threats to biodiversity include loss of habitat, pollution of surface and ground water by nitrogen fertilizer
run-off, and the impacts of pesticides, such as the neonicotinoids (see “Neonicotinoids – A Primer” in the
ECO’s 2014/2015 Annual Report). Biodiversity loss is a major issue, both in Ontario and internationally, with
many species and even classes of creatures (e.g., amphibians) experiencing various levels of population
decline.28, 29 Not all of these problems are directly attributable solely to agricultural practices, but all of them are
impacted to some degree by the way in which we grow our food. Moreover, many of these threats (if not all)
may be exacerbated by climate change, and in particular the potential increase in frequency of extreme
weather events.
Time to Change Course
The combined effects of climate change and growing environmental harm present a substantial challenge to
modern agriculture. The steady stream of agricultural innovations has to date not been sufficient to fully
address all of these environmental problems.30 This may be the result of the fact that many conventional
solutions address the symptoms, rather than the causes, of a
If you scoop a handful of
particular environmental problem. For example, buffer strips
(areas of permanent vegetation designed to trap sediment and
soil from an average home
slow down run-off) have long been advocated as a way to
garden, you will hold in your
control phosphorus pollution from farms. However, some
palm more organisms than
experts31 feel that they are simply band-aid solutions, marginally
effective at best, because they don’t address the roots of the
there are humans on the
32
problem, which vary from farm to farm. Accordingly, they are
planet.
subject to failure under certain circumstances, such as in winter,
when the ground is frozen and phosphorus-laden water can flow
right over them, and they do not address in any manner at all phosphorus loss through tile drains.33, iv
Moreover, they impose a penalty on the farmer (a loss of arable land) without offering any personal pay-back in
Farms in Ontario vary considerably with respect to the amount of phosphorus in their soils: some have excessive levels;
some have levels appropriate for crop needs; and some are deficient and require supplementation. Also, some P is in
organic form, while other P is soluble, and it is primarily the latter that is leaving farms. Cover crops (see p. 20) are a more
iv
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
return. As a result, the land these buffers take up may be brought back into agricultural production by farmers
if the economic environment changes.
Some modern agricultural methods work against, or at least in ignorance of, the natural processes that
underlie sustainable ecosystems. If their main purpose is to optimize yield or reduce labour costs, they often
don’t take sustainability into account. Alternatively, if they are meant to address a sustainability issue like
erosion, they often do so by trying to control the symptom, rather than addressing the cause, as in the
example above. A new approach is required, one that is sufficient to solve the many environmental problems
outlined here, particularly those related to climate change, without foregoing the productivity and profitability of
modern agriculture.34
efficient way to deal with phosphorus issues, as they take up excess P and hold it for future crops, regardless of the
circumstances on an individual farm. This approach benefits both the farmer and the environment.
PUTTING SOIL HEALTH FIRST
11
Putting Soil Health First
The “new” way forward already exists: the soil health approach. Failure to understand, and respect, basic soil
biology has been the biggest weakness of conventional agriculture.35,36 Addressing this weakness offers
significant good news, for greenhouse gas emissions, adaptation to climate change, and for the environment
in general.37 The ECO has been following this agricultural management trend, with growing optimism, for
almost a decade. Here, we share what we have learned and explain why we think that soil health is such a big
deal.
What is Soil Health?
The complex, busy world beneath our
feet
First of all, let’s consider what the term
“soil health” means. The word “health” is
not usually associated with inanimate
objects, let alone complex mixes of
ground-up minerals, organic matter,
water, and air. However, inherent in the
term soil health is an obvious hint at a
not-so-obvious truth: soil is alive.38 Not
alive in the same sense as an organism,
but rather in the sense of an
ecosystem.39,40
Figure 3: The Soil Food Web.
Source: Soil and Water Conservation Society (SWCS). 2000. Soil Biology Primer.
Rev. ed. Ankeny, IA: Soil and Water Conservation Society.
12
The thin layer of topsoil that covers most
of the dryland surface of the planet
constitutes a varied set of enormously
productive and dynamic ecosystems.41 If
ENVIRONMENTAL COMMISSIONER OF ONTARIO
you scoop a handful of soil from
an average home garden, you will
hold in your palm more organisms
than there are humans on the
planet.42 Moreover, they are very
busy organisms. As one noted
soil ecologist puts it: “It’s like
Times Square on New Year’s Eve
all the time” in the soil.43
It is the myriad of tiny creatures
living in the water/air mixture that
fills the pore spaces between
grains of sand, silt, or clay that
determine whether a soil is
healthy. Scientists refer to this
underground society of microbes,
arthropods (e.g., insects, spiders,
crustaceans), worms and other
organisms as the soil food web
Figure 4: Soil organisms within a soil aggregate
(see Figure 3). Like the aboveSource: Soil and Water Conservation Society (SWCS). 2000. Soil Biology Primer. Rev.
ground food web, the soil food
ed. Ankeny, IA: Soil and Water Conservation Society.
web can be thought of as a
multitude of different types of organisms and the set of ecological relationships between them. Some are
predators, some are prey, but many are both.
At the very bottom of the food chain are the bacteria and fungi, who are the principal decomposers, breaking
down and consuming dead organic matter. These microscopic organisms constitute the main food source for
larger predators such as nematodes, protozoa and the smaller arthropods, which in turn are the prey of the
predatory nematodes and larger arthropods. These latter creatures, along with various types of earthworms,
occupy the top rung of the soil ecosystem underground, but they themselves are prey to many above-ground
creatures, such as insectivorous birds and burrowing mammals. In fact, the connection between soils and the
ecosystems above them is so strong that scientists usually find that population and biodiversity levels above
ground reflect those below, and vice-versa.44,45
The substantial benefits of healthy soils
Humans have been aware of the importance of this complicated below-ground world for a very long time.
Aristotle referred to earthworms as “the intestines of the earth,”46 because of their ability to cleanse the soil
PUTTING SOIL HEALTH FIRST
13
(e.g., destroy pathogenic organisms) and recycle organic residuals into nutrients. However, despite the fact
that soils provide many important ecological benefits (see discussion below), including many related to human
health,47 modern agriculture’s focus, for the most part, has been restricted to soil’s ability to recycle nutrients,
and even that role has been almost totally usurped by synthetic fertilizers. Only recently has awareness of
other important soil-food-web functions started to seep into the world of conventional agriculture.
A soil “function” is a regular ecological service provided by the soil to the environment at large.48 Ninety per
cent of these functions are biologically driven,49 which is why the soil food web is so important. The organisms
of the soil food web create what we define as healthy soils by:
•
•
•
•
•
making nutrients available to plants in a variety of unique and effective ways (see “The Original Carbon
Trading Scheme,” pp.15-16);
building and enhancing soil aggregation and porosity (good soil structure), which allows better water
infiltration and holding capacity (see “The Soil’s Structural Engineers,” below);
sequestering nitrogen and other nutrients in their bodies, reducing nutrient loss as pollution;
preying on and/or out-competing disease and pest organisms, enhancing plant health and increasing
crop yields; and
increasing organic matter in soils, a basic activity that not only supports all of the above functions, but
also reduces carbon levels in the atmosphere, mitigating climate change.50
Bacteria and Fungi: The Soil’s Structural Engineers
By far the most numerous members of the soil food web are the bacteria and fungi. Yet despite their tiny size and their lowly position at
the bottom of the food web, these microbes are the soils most important engineers, because they build good soil structure.51
Soil consists of particles of various sizes, from tiny, barely visible clay particles (less than 0.02 mm), through slightly larger silt particles
(up to 0.05 mm), to large and easy-to-see grains of sand (up to 2 mm). Soil with more than 50 per cent clay particles is considered a
“clay soil”. In these soils, the small particles can fit very closely together, leaving only very tiny pore spaces. In fact, clay soils often
compact so much that water just sits on top of them as though they were made of concrete. At the other extreme are sandy soils,
where the spaces between the grains are larger (imagine golf balls in a jar). These soils can often be dry, because water drains through
them very easily. The best soils have a good balanced mixture of clay (20 per cent), silt, and sand (40 per cent each); these are known
as loam soils.52
All types of soils, however, require good internal structure to be healthy. This structure can vary from poor to excellent, and although it
is influenced by soil type, chemistry, and the environment, its final form is largely the result of biological activity. Bacteria, fungi, and
earthworms all secrete organic glues, which stick to the tiniest particles and cause them to cling to each other, forming small
aggregates. In particular, a substance call glomalin,53 produced by mycorrhizal fungi, seems to be very important in this process.54, 55
Fungi of all types then enhance this process by wrapping their hyphae (filaments) around the smaller aggregates, bunching them
together into larger ones.56,57 It is this mix of aggregates of various sizes that gives soil its optimum structure. In a well-aggregated soil,
water can infiltrate freely, preventing puddling, run-off and flooding. The water is also held tightly in the pore spaces, where it is
available for later use by plants.58 Finally, and perhaps most importantly, these aggregates don’t break down when the soil gets wet,
because the glues and the hyphae are strong and water-resistant. In summary, a soil with good structure prevents flooding and run-off,
resists drought, and does not easily erode. It is roomy, stable, and well stocked with water and air – an ideal home for both microbes
and plant roots.59,60
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
The Original Carbon Trading Scheme
How plants get their nutrition
As Ontario gets ready to initiate a “cap and trade” carbon market, it might be instructive to take a look at the
original carbon market – the one that has been going on underground since plant life first appeared on the
planet.
Any review of underground carbon trading should begin with a look at how plants obtain their soil-based
nutrients. The first two concepts to understand are mass flow and diffusion.
Soil particles are usually surrounded by a thin film of water. As plant roots take up water from the surrounding
soil they create a moisture gradient, i.e., the soil is drier closer to the roots. Water gradually moves along this
gradient, from areas of higher moisture towards the lower moisture levels near the roots; this natural process is
called mass flow. This water carries many nutrients with it.
Bacteria swarm root tip (rhyzosphere)
Source: Soil and Water Conservation
Society (SWCS). 2000. Soil Biology Primer.
Rev. ed. Ankeny, IA: Soil and Water
Conservation Society.
At the same time, a similar process is occurring for all nutrients
within the soil water. Diffusion is the tendency for substances in
solution to move from regions of high concentration to those of
lower concentration, thus evening out their distribution. Because
plants are regularly absorbing nutrients in the root zone (known as
the “rhizosphere”), nutrient concentrations near the roots are
usually low compared to the soil in general. Accordingly, nutrients
diffuse toward the roots, independent of (and supplementing)
mass flow. Together, these two processes result in a steady
movement of dissolved nutrients towards plant roots. In effect,
roots “suck up” water-soluble nutrients for the plant from the
surrounding soil.61
When these nutrients reach the roots, they are absorbed, in what
is largely a passive manner, via diffusion across the root cell walls.v
The above description of how plants get their nutrition used to be
considered the full story; however, that view has changed with the
emergence of new information from the discipline of soil ecology. To understand how the above system is
substantially enhanced by the soil food web, we can start with a couple of questions: first, where do nutrients
originate in soil and how are they replenished? And second, how do relatively slow and passive processes like
Plants do have some specialty mechanisms for controlling this process, but in general nutrient take-up is passive in
nature. The movement of nutrients upwards to the plant from the roots creates a lower concentration in the root cells than
in the surrounding soil water, resulting in diffusion.
v
PUTTING SOIL HEALTH FIRST
15
…plants use photosynthesis to
fix carbon in an organic form
from CO2 in the atmosphere.
They then trade a portion of
that carbon currency to
microbes, in return for fast and
efficient nutrient delivery.
diffusion and mass flow possibly provide enough nutrients
for the lush growth of a prairie, or a forest? The answers to
these questions are closely related; both involve soil
microbes.
Nutrient sources
Plant nutrients (e.g., phosphorus, potassium, calcium,
boron, manganese, zinc, etc.) come primarily from two
sources in natural systems: mineral rock (in the form of clay,
silt, or sand particles), or, in the case of nitrogen,
atmospheric nitrogen gas; and dead organic matter.62
Nutrients contained in a rock particle or in organic matter
(e.g., a dead root) are insoluble and cannot diffuse into plant root cells.63 Weathering breaks down the
minerals over time, but this process is extremely slow. Fortunately, however, microbes such as bacteria and
fungi have the ability to break down both mineral and organic
materials fairly quickly and incorporate the various constituent
nutrients in their bodies. When these smaller microbes are later
consumed by larger microbial predators, such as protozoa and
nematodes, some of these nutrients are released, in a soluble
form, in the predator’s excrement. These nutrients are now “plantavailable”; that is, they are water-soluble. Mass flow and diffusion
can now deliver them to the rhizosphere, where they diffuse into
plant root cells.64 In nature, most plant nutrients are cycled and
recycled in this way.65
Faster nutrient delivery
Freeing nutrients from their mineral and organic forms is not all that
microbes do. They also provide plants with some faster delivery
mechanisms. This is where carbon comes in; plants use
photosynthesis to fix carbon in an organic form from CO2 in the
atmosphere. They then trade a portion of that carbon currency to
microbes, in return for fast and efficient nutrient delivery. Two basic
systems exist to do this.
One system involves the release of carbon-rich compounds, such
as sugars and amino acids, from plant roots (“root exudates”) into
the soil of the rhizosphere.66,67,68 Microbes are attracted to the roots
by this high-energy feedstock and, in turn, microbe predators (e.g.,
nematodes) are also drawn in to feast on the microbes. As they do
16
Vesicular Arbuscular Mycorrhizal (VAM)
fungi are the most common type in farming
systems; there are about 240 different
species. They are often numerous, and
can comprise 20 to 30 per cent of all soil
microbial biomass. They invade root cells,
where they create vesicles, or storage
structures. This picture shows the
mycorrhizal structures (vesicles) within root
cells.
Source: Source: S.L. Sturmer and M.
Brundrett. 2016, Global Soil Biodiversity
Atlas. European Commission, Publications
Office of the European Union,
Luxembourg.
ENVIRONMENTAL COMMISSIONER OF ONTARIO
so, they excrete soluble nutrients right where the plant needs them – just outside the root cell walls.69 On
average, 17 per cent70 of the carbon compounds that plants produce through photosynthesis are dedicated
to this purpose (the amount can go as high as 44 per cent).71
The second system consists of an even more direct type of symbiosis. A type of fungi called “mycorrhizae”
(Latin for “fungus roots”) burrows into plant roots (some types even penetrate the root cells) and create the
equivalent of a two-way pipeline, with carbon-based substances from the plant flowing outwards to provide
energy for fungal growth, and water and nutrients flowing back through those strands to the plant. These
mycorrhizal filaments (called “hyphae”) greatly extend the foraging area of the plant while speeding up and
enhancing its access to nutrients.72,73
In summary, the original carbon trading system is an important and ubiquitous underground activity that
benefits all participants, both below and above the surface. Plants trade with microbes, providing a significant
portion of the carbon compounds that they produce through photosynthesis in return for greater and faster
access to nutrients and water.
Carbon trading and sequestration
This complex system of underground carbon trading results in a pool of “labile” or active soil carbon that is
always in flux. Microbes respire, just as animals do, and they release carbon back into the atmosphere as CO2
on an on-going, regular basis. However, if the carbon coming in from the plants is greater than carbon going
out through microbe respiration, soil-carbon levels rise overall.74 This accumulation of carbon in the soil is what
we call soil-carbon sequestration,75,76 and it is very important in both mitigating and adapting to climate
change.77
Carbon-nutrient exchange systems are extremely susceptible to disruption by poor soil management practices
by humans. Some, such as aggressive tillage, increase carbon losses by making more oxygen available,
increasing microbial respiration and releasing more CO2; others, such as leaving soil bare for long periods of
time, or using chemical inputs indiscriminately, slow down the carbon trading system between plants and
microbes by limiting photosynthetic inputs and/or reducing microbial numbers and diversity (see “Throwing
Sand in the Gears,” p.19).
The Soil Health Approach – Principles and Practices
The many benefits of healthy soils, as described above, are readily available to farmers, provided that the size
and diversity of the soil food web is maintained. The next logical question, therefore, is how best to manage
the soil in a manner that supports and enhances its living components, in order to maximize their potential. As
it happens, leaders in the soil health field have been formulating key management principles and practices for
the past couple of decades.78
PUTTING SOIL HEALTH FIRST
17
Principles
Key soil health principles include the following:
•
Keep the soil covered at all times. Good soil cover (crops, cover crops, and/or crop residues)
means that soil moisture is conserved and temperatures are moderated. This practice protects the
underground habitat of soil organisms, encouraging their growth and activity. Surface residues feed
the soil food web by providing organic matter for microbes to feed on; main crops and cover crops
feed the microbes with their root exudates (as discussed above).
•
Maximize diversity.79 A wide diversity of plants
The many benefits of healthy
above ground leads to a greater diversity of food for
beneficial soil microbes.80 This is because different
soils….are readily available to
crops release different types of root exudates,
farmers, provided that the size
attracting and supporting more below-ground
and diversity of the soil food
diversity.81,82 They also have different types of roots,
web is maintained
with varying lengths and forms, improving the soil
over a greater range of depths. This greater microbial
diversity results in a deeper and more resilient set of soil functions;83 therefore, growers experience
higher levels of productivity,84 increased disease resistance in crops, reduced pest problems, and
overall greater resilience85 to environmental impacts such as drought, extreme weather events, and
temperature fluctuation.
•
Minimize soil disturbance. (i.e., no-till, or minimum tillage). Tillage disturbs the soil food web, altering
the balance between bacteria and fungi. Ploughing breaks the fungal hyphae, slowing fungal growth
and reproduction.86 Fungi are very important for soil structure (see “The Soil’s Structure Engineers,”
p.12) and also for disease suppression, as beneficial fungi can out-compete and suppress pathogenic
(disease-causing) fungi under good soil conditions. Tillage also exposes decomposer bacteria to
higher levels of oxygen, speeding up the decomposition of organic matter. This releases CO2 to the
atmosphere too quickly (i.e., faster than it can be replaced), reducing overall soil organic matter levels.
Reduced soil organic matter then depletes the fungal populations further, resulting in a loss of stable
soil aggregates. This leads to further carbon loss, as well as erosion and compacted soils.
•
Keep live roots in the ground for as much of the year as possible (including over winter). Live roots
feed the soil food web, via exudates. In particular, mycorrhizal fungi cannot survive without live roots as
hosts; bare fields deplete mycorrhizal populations, depriving the following year’s crop of their abundant
benefits.87
Use organic inputs. Organic materials, such as crop residues, manures and compost, provide
habitat and feed for the soil food web while generating fewer of the potential harmful side-effects of
synthetic inputs (see “Throwing Sand in the Gears,” below). However, any nutrient, whether natural or
synthetic, can cause problems if not applied wisely (see Best Management Practices below).
•
18
ENVIRONMENTAL COMMISSIONER OF ONTARIO
Throwing Sand in the Gears: How the Inappropriate or Over Use of Synthetic Inputs Can Impair the Natural System
Heavy use of synthetic fertilizers is de-emphasized in the soil-health approach.88,89 This is because these chemicals can do more
damage than good if they are not carefully deployed (see Klaas Martens case study, pp. 23-24). When not used in this careful manner,
the negative impacts of fertilizers can be direct or indirect. Direct impacts include: the release of N2O, a very potent greenhouse gas90
(as in Figure 2); pollution of groundwater;91 depletion of soil carbon by decomposer microbes stimulated by excess nutrient
availability;92,93 reduced diversity of soil organisms;94,95,96 and increased weed pressure, also caused by an excess of readily plantavailable nutrients.97, 98
An important indirect problem involves plant-root exudates. One of the main reasons that plants release these exudates is to feed
microbes in their root zone99 (see “The Original Carbon Trading System”). This comes at an energy cost to the plant, so if it can acquire
the nutrients it needs without having to attract the microbes, it gradually reduces the quantity of exudates.100 This reduces one of the
soil food web’s major food sources, which in turn limits the quantity and quality of the services that the soil food web can provide.
Pesticides can also be problematic, in that many of them impact the soil food web negatively, usually by reducing diversity.101,102
Fungicides, for instance, hurt many beneficial fungi as well as the target pests.103 Since fungi are increasingly recognized by scientists
as crucial to soil health, carbon sequestration,104,105,106 and natural productivity,107,108 (as well as having been shown to suppress some
aggressive weeds),109 knocking them back with fungicides on a regular basis will reduce these benefits. The soil health approach
depends on the natural defenses of soil and of plants for the bulk of its crop protection; accordingly, pesticides of any kind are used
very carefully and/or infrequently.110 ,111
Best Management Practices
The underlying theme to all of the above principles is protect and enhance soil life. The soil health approach is
strongly focused on maximizing the benefits of a healthy, diverse, and productive soil ecosystem. These basic
soil health principles can be implemented by means of a variety of soil health best management practices
(BMPs). The following is a brief summary of the most important
BMPs.
-
-
Conservation tillage. This practice consists of a number of
methods of soil cultivation that leave the previous year’s
residues on the field. The most common examples are no-till
and strip-till. The former involves planting crops into residue
that has not been tilled at all; the latter involves planting crops
into narrow strips of tilled soil, with the rest of the soil and
residues left untouched. These practices address to varying
degrees112 the principle of minimizing soil disturbance, thus
Equipment adapted for no-till by the
supporting and enhancing the soil food web in a variety of
Belans (see pp. 24-25).
ways.
Source: Glenn Munroe
Crop rotations. This is the practice of planting different crops
in the same field following a defined order (e.g., corn-wheatsoybean). Rotating crops has been shown to have a number of benefits, including increased overall
production,113 reduced pests and diseases,114 weed control,115 and improved soil health.116 This practice
addresses the principle of maximizing diversity, while also minimizing the disease pressure that can arise
from having the same crop in the same soil year after year.
PUTTING SOIL HEALTH FIRST
19
-
-
Cover crops. Growing crops intended for purposes
other than harvesting them for sale can have substantial
…focusing on soil health is
benefits. They can reduce soil erosion, add organic
not just good environmental
matter, reduce nutrient losses, improve soil fertility,
practice; it is good business
reduce pest populations, reduce soil compaction, and
117
generally improve soil health. They accomplish these
practice as well
benefits by addressing three important soil-health
principles: keeping the soil covered, maximizing diversity
and keeping live roots in the ground.
The 4Rs of fertilizer use. The 4Rs approach represents a sustainable way of applying synthetic
fertilizers to crops. It means: right source (balanced nutrients in plant-available form); right rate (based on
soil nutrient supply and plant demand); right time (based on dynamics of crop uptake, soil supply, nutrient
loss risk, etc.); and right place (where roots can access the nutrient and losses are limited).118 This
practice addresses the concerns expressed in “Throwing Sand in the Gears” on p. 19, while ensuring that
the crop has the level of plant-available nutrients required to produce a good yield.
-
Composting and compost utilization. Wherever feasible, composting an organic amendment before
applying it to the soil is preferable because composting stabilizes materials such as manure, reducing runoff (and thus nutrient loss and pollution) and increasing soil-carbon sequestration rates.119, 120
-
Livestock integration. The modern approach to raising livestock, in which animals have been separated
from crop production, has, as farmer/writer Wendell Berry puts it, taken “a solution and divided it neatly
into two problems.”121 By appropriately re-integrating livestock with growing crops, farmers can reduce the
use of synthetic fertilizer, boost soil health, and increase soil organic matter. At the same time, one of
agriculture’s largest methane sources (from stored manure) would be greatly reduced. This practice
addresses the principle of adding organic soil amendments, as well as keeping the soil covered and live
roots in the ground (because livestock can graze on cover crops).
Use an ecological approach to grazing management. Farmers who raise livestock on dedicated
pasture lands also have the ability to improve soil health and increase soil carbon. Both the method and
the duration of the grazing are important. Rotational or “mob” grazing is a system whereby animals are
kept in small grazing areas for short periods of time (as opposed to having the entire, large grazing area
available to them all of the time). Having to compete for what they eat ensures that they graze all the
vegetation (rather than just selecting the plants they like most), while moving them frequently to new
grazing areas prevents over-grazing. The prevention of over-grazing ensures the retention of a significant
capacity for photosynthesis, allowing the vegetation to recover quickly when the animals have moved on.
In addition, livestock manures provide readily available nutrients, creating greater soil fertility. This
approach mimics the way large herbivores lived on the prairies before humans began to interfere: grazing
animals were kept bunched up and moving by predators, eliminating over-grazing and reducing selective
grazing. Properly managed rotational grazing systems have been shown to significantly increase soil
carbon, reduce and even reverse degradation, maximize diversity, and promote healthier soils.122,123
-
20
ENVIRONMENTAL COMMISSIONER OF ONTARIO
Farmers who adopt and systematically apply the principles and practices outlined above are able to gradually
but dramatically reduce inputs, maintain or increase their yields, increase the water-holding capacity of their
soils, virtually eliminate environmental problems, and become much more profitable – all at the same time.124
As the examples that follow demonstrate, focusing on soil health is not just good environmental practice; it is
good business practice as well.
PUTTING SOIL HEALTH FIRST
21
Champions of Soil Health
The most well-known North American champions of soil health farm in the United States, where the Natural
Resources Conservation Service (NRCS – see p. 29) has been working with innovative farmers to lead, foster
and promote the soil health movement over the past few years. Meet two leading U.S. soil health champions,
one conventional and the other organic. Their stories show the inspiring extent of what can be accomplished
by farmers who put soil health first.
U.S. Soil Health Champions
A no-till farmer shows a multitude of
worm middens, a characteristic of
healthy soil
Source: Glenn Munroe
22
Brown Ranch, North Dakota
Gabe Brown and family operate a 5,400-acre ranch, including
2,000 acres of cropland, near Bismarck, North Dakota.125 Brown
began his gradual transition to a soil-health focused approach in
1993, when he converted his cropland to a no-till operation. At that
time, his soil’s organic matter levels (which correspond closely to
soil carbon content) averaged less than two per cent. In 1995 he
took his next step, which was to begin to diversify his rotation. By
that time he had noticed a slight improvement in his soil.
Encouraged by this improvement, in 1997 he introduced cover
crops. His soil continued to improve, with organic-matter levels
rising and water-holding capacity and infiltration rates increasing
year after year. In 2006, he began to experiment with multi-species
cover crops (to further increase diversity) and since then he has
ENVIRONMENTAL COMMISSIONER OF ONTARIO
also integrated his grazing animals (cattle, sheep, pigs) into his
cropland management. In the slightly more than two decades
that he has been managing for soil health, the average organicmatter levels in his fields have risen to between 5.3 and 6.1 per
cent, with one field recently reaching 11.1 per cent.vi
Brown has calculated that he
can produce more calories
per acre with his soil-healthbased system than any other
farming system that he knows
of, and at less cost
These management practices, however, have done a lot more
than just sequester carbon. Brown states that they have
demonstrably increased the size and diversity of the food web in
his soil, with all the associated benefits. His land can now
absorb over eight inches of rain per hour, a precipitation rate almost never reached in his area. Accordingly,
when his neighbour’s land is flooded after a heavy rain, he does not even see puddling on the surface of his
land. Nor does his land generate any run-off, regardless of the time of year. In fact, Brown states that the
water-holding capacity of his land has increased to about 20 inches, which is 5 inches more than the average
annual rainfall in the Bismarck area. What this means is that his soil is able to capture and hold all of the rain
that falls each year in his region, protecting his crops from drought and increasing his yields.
With respect to the efficiency of his yields, Brown has calculated that he can produce more calories per acre
with his soil-health-based system than any other farming system that he knows of, and at less cost. His yields
are about 25 per cent higher than the county average, yet he uses no fertilizer, no insecticides, and no
fungicides; he stated in 2015 that he makes only one herbicide pass on some of his fields every two to three
years, and that he is working to eliminate that. His per-acre costs are much lower than average and he
believes that he is easily the most profitable operation in his area.
Klaas and Mary-Howell Martens, organic farmers, New York State
Most conventional farmers would be more than pleased with a yield of 200 bushels of corn per acre,126 a
figure well above the 2015 New York state average of 143.127 Yet the Martens achieve this high yield level
while growing organically, without the assistance of any synthetic fertilizer or pesticides. Usually, organic
farmers struggle to meet the average yield in their area, let alone exceed it by 40 per cent. How do the
Martens accomplish this apparent anomaly? The answer is that they do it by focusing on soil health.128
The Martens, who farm in upper New York State, embrace the organic philosophy but also the concept of soil
health and the practices that sustain it. They expand on the usual definition of soil health by adding that it is
also important to create an environment in the soil that is suitable for the crop being grown. They believe that
the lower yields (compared to conventional) that many organic farmers have come to expect is due to the way
in which they farm, which is to farm conventionally but with organic inputs. The Martens take a different
North Dakota has a very different climate than Ontario, with less rain and drier soils, conditions considered more
amenable to soil organic matter accumulation. However, the soil-health benefits experienced by farmers in Ontario will be
similar to those in North Dakota, if not necessarily to the same extent or scale.
vi
PUTTING SOIL HEALTH FIRST
23
approach; they strive to create the most suitable soil environment for each crop by mimicking natural
succession. Accordingly, they plan both their type and timing of soil management (amount of tillage, cover
crops, etc.) and their crop rotations to ensure that each crop they plant is growing in a soil that is best suited
for it.
They have worked closely with researchers at Cornell University to expand on their knowledge of soil health
and the practices that promote it. In doing so, they have discovered that too much fertilizer, even organic
manure, is not only a waste of money and an environmental risk, it is also an invitation to weeds, which thrive
in soils rich in readily available nutrients. At the same time, they have discovered that nitrogen is almost never a
limiting factor in healthy soils, where nitrogen-fixing legumes are part of the mix of covers and/or rotation.
Therefore, by applying only modest amounts of manure (1.5 tons per acre) at the right time (on an actively
growing crop the season before), they get significantly less weed pressure, lower costs, no environmental
impacts, and good yields.
The Martens have learned a lot about soil health, and their knowledge allows them to out-perform most
conventional growers without using any synthetic inputs. They report that their soils are so healthy that
diseases that plague their neighbours’ conventional crops bypass their own crops, and sometimes actually
attack only the weeds on their fields. Klaas Martens feels that this is because they have not only optimized the
health of their soils, but also fine-tuned them for each specific crop. This means that their crops are able to
withstand pest and disease pressure much better than the weeds.
Ontario Soil Health Champions
Here in Ontario, a small but growing group of farmers are putting more of a focus on soil health and are
reaping the benefits of higher yields, lower costs, and fewer environmental impacts. The ECO profiled three
such innovative soil health leaders in a previous reportvii and we are
pleased to celebrate two more: the Belan farm, located north of
Chatham, and the Rogers farm, in Lambton Shores.
Mike Belan demonstrates the excellent
structure of his healthy soil
Source: Glenn Munroe
The Belan family farm, near Inwood, Ontario.
As Mike Belan describes it, his family was led into the world of soil health
by financial circumstance. The high interest rates in the 1980s forced
them to sell off some land and equipment in order to pay some debts to
the bank; at the same time, it caused them to rethink the way they were
farming. Mike’s father, a young man at the time, was in the process of
taking over the management of the farm from his father. He found that he
didn’t like working so many hours just to pay interest to the bank. So, in
vii
See “Healthy Soils Yield Benefits for Ontario Farmers” on page 63 of Managing New Challenges, the ECO’s 2013/2014
Annual Report.
24
ENVIRONMENTAL COMMISSIONER OF ONTARIO
1991, when an equipment manufacturer introduced a 30-foot
no-till drill to the Ontario farming community, they decided to
give it a try. The next year, they converted to a full no-till
operation and sold all of their tillage equipment and
unnecessary tractors. Then, as Belan says, they “began the
adventure that is no-till farming.”
…“our low cost of production
with no-till” means that “we
don’t need to hit a homerun
with yields every year”
– Mike Belan
They endured some difficulties, including what the agricultural
community calls “yield drag” (a reduction in yield in the first few years often experienced in the conversion to
no-till). However, the family persevered, and Belan is very grateful that they did, for their yield is now slightly
above average for their region, while their productions costs are much lower than they would be if they were
tilling. They also notice that their soils are better able to handle weather extremes; they don’t experience
drought conditions and their land can handle noticeably more rain than can their neighbours.
Belans seeding corn into a green cover
Source: Mike Belan
After no-tilling for more than 20 years, the Belans’ first experience with cover
crops came in 2013, when they allowed volunteer wheat to remain in the
field after wheat harvest (their normal practice was to spray in the late fall to
have a clean field in the spring). They liked what they saw in the spring, so in
2014 they planted a four-way mix of cover crops after the wheat harvest in
August. This stayed green through the winter and they planted corn right
into it in the spring of 2105. Since then, they have introduced the practices
of inter-seeding into standing corn (so that the cover crop will have a head
start when the corn is harvested) and also planting into a green cover crop
in the spring. Belan states that although they have been very successful
with the cover crops so far, this approach takes a great deal of
management in the springtime, making it a “very stressful time of year.”
They are now planting some sort of cover crop on all of their acreage, both owned and rented, and recently
tried a 14-way mix in a test plot. One of the first noticeable benefits of the cover crops has been the condition
of the soil in spring; the top two inches of the soil is more “mellow” and allows better seed-to-soil contact.
They also introduced grid sampling about four years ago. They do a basic soil test, which includes macro and
micro nutrient availability as well as soil organic matter. This allows them to fine-tune their fertilizer applications
across the entire farm.
Mike Belan says that they are quite pleased with their current situation, because the “low cost of production
with no-till” means that they “don’t need to hit a homerun with yields every year” and they are content to see
their production “consistently trending upwards.” Their levels of soil organic matter have gone up from around
2 per cent when they started no-tilling 25 years ago, to around 5 per cent (high 4s to low 5s) in 2016.
PUTTING SOIL HEALTH FIRST
25
The Rogers farm, Lambton Shores, Ontario
Doug Rogers and his family grow soy, corn and wheat on 700 acres
of land (owned and rented) situated less than two kilometers from
Lake Huron. He transitioned in 1990 to a combination of ridge till and
no till but has been strictly no till for the past 16 years. He uses a
“controlled traffic” system on his fields to avoid soil compaction, which
means that he has planted in the same rows year after year. He
planted his first cover crop in 2010, following winter wheat with oats
and tillage radish. He has since evolved into a multi-species cover
cropper (8-10 species). For the past two years he has been interseeding several covers into standing corn and a single cover of
annual rye into his soy crops. As of 2016, he is also adding
municipally derived “green bin” compost to his fields, applied after
winter wheat harvest and prior to planting the cover crops. His goal is
to increase the organic matter on his light loam soils as quickly as he
can.
Rogers Farm: This is one method used to
stop surface erosion. This farm has ten feet of
fall from front to the back of the field of
brisbane loam soil
Source: Doug Rogers
Rogers initially introduced cover crops as a way to increase soil
health, build organic matter, and to drought-proof some of his lighter soils by building up their water-holding
capacity. Now he is seeing other benefits as well, including weed suppression and more biological life in his
soils. He is hoping to be able to start cutting back on all of his synthetic fertilizers in the next few years. In
2013, Rogers became interested in finding out whether he is holding on to more of his topsoil and
phosphorus as a result of his efforts. He approached the St. Clair Conservation Authority and asked if they
would set up a small water quality project testing tile outlets of different fields to compare their results during
precipitation events. They agreed. Early results, from 2014 and 2015, show that water from tile drains coming
off Rogers’s land, compared to that of nearby conventionally worked fields, contained: less than half the level
of total dissolved solids (TDS); a fraction <10 per cent) of the total suspended solids (TSS) in 2014 and half in
2015; 29 per cent (2014) and 46 per cent (2015) of the nitrogen; and 36 per cent (2014) and 67 per cent
(2015) of the phosphorus.129
These are good results and are likely to get better over time, as he
has only been doing multi-species cover crops for a few years and
“We now strive to
he has not yet started to reduce his fertilizer inputs. Rogers recently
maintain a ‘living crop’ on
authored an article for the St. Clair Region Soil and Crop Newsletter,
where he wrote: “We now strive to maintain a ‘living crop’ on our
our fields year round”
fields year round…The residue left behind is a food source for the
– Doug Rogers
biological network under our feet. Soil micro-organisms help improve
soil structure, and create better soil aggregates. This provides better
water infiltration into the soil profile so it will not run off the fields.”130
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
Like the Belans, Rogers reports that his yields are just as good or better than township averages and he does
not feel that he has experienced any long-term yield drag. Most importantly, his net return is higher than that of
his neighbours because of lower input costs and less equipment overhead. This improved financial status has
been the case with all of the soil-health focused farmers that the ECO has profiled over the past few years; it
really does appear that when it comes to healthy soils, there is synergy, rather than conflict, between the
environment and the economy.131
PUTTING SOIL HEALTH FIRST
27
Realizing the Promise of Soil Health
A Role for Research
These soil health champions provide compelling, if anecdotal,
evidence that the adoption of soil-health based systems by farmers
could make a significant impact on the environmental footprint of
agriculture, while maintaining the high productivity and low costs that
the market demands. Now what is needed is more focused
research on the specific mechanisms at work in healthy soils, and a
respectful conversation with farmers on how to implement these
principles and practices.
Beneficial nematodes: These creatures enhance
soil fertility by preying on bacteria and fungi,
releasing nutrients
Soil biology is complicated and difficult to study. However, recent
Source: Soil and Water Conservation Society
(SWCS). 2000. Soil Biology Primer. Rev. ed.
advances in molecular technologies and DNA sequencing are
Ankeny, IA: Soil and Water Conservation Society.
allowing researchers to gain a more detailed and comprehensive
view into the world of soil and soil organisms.132 This type of research is in its infancy, but already producing
fascinating results.133 For instance, researchers have discovered that it takes a consortium of 17 microbes,
rather than a single species, to reliably and consistently suppress a commercially important root disease of
sugar beets.134 With this kind of information, suppliers may be able to come up with biological solutions that
can be counted on to effectively address specific pests and diseases.135 In fact, large multinational companies
like Monsanto have already set up biological research arms that are working to develop these types of
products.136,137
While an important role for commercial suppliers is inevitable in the soil health movement, the fundamentals of
soil health should not be left entirely to the profit motive. The ECO believes that the OMAFRA should take a
stronger role in identifying, supporting and communicating the soil-health research that Ontario farmers need
to help them make management decisions.
28
ENVIRONMENTAL COMMISSIONER OF ONTARIO
What are Other Jurisdictions Doing?
Two leading jurisdictions on soil health are the United States and
France.
United States
The Natural Resources Conservation Services (NRCS), a branch of
the United States Department of Agriculture (USDA), has a lengthy
and distinguished history. In the early 1930s, persistent drought,
failed crops, and lack of soil cover on the Great Plains of America
created what came to be called the Dust Bowl: huge clouds of
topsoil were blown across America, over top of Washington, D.C.,
and out into the Atlantic Ocean. In response to this crisis, the
Roosevelt administration passed the Soil Conservation Act, which,
among other things, created the Soil Conservation Service. The
mandate of the service was to promote soil conservation, which it
has done by means of an ever-expanding variety of programs and
incentives over the past eight decades.138 Its name was changed
to NRCS in 1994.
Alternating strips of corn and soybeans on a notill farm in Ontario
Dean Glenney’s “fence-row” farming system, which
combines no-till, crop rotations, and precision
agriculture to achieve extremely high yields, was
featured in the ECO’s 2013/2014 Annual Report:
Managing New Challenges.
Source: Glenn Munroe
Recently, NRCS has become a prominent leader in the soil-health movement, influencing many other
organizations and jurisdictions, including Ontario. In 2012, NRCS launched a soil health campaign, which
included providing soil health training to thousands of its own field officers, as well as to thousands of farmers
and ranchers. Then, in 2014, NRCS created a training team of soil health experts, which delivered training and
outreach at more than 200 soil health events across the United States in its first few months. It has also
developed a series of webinars and YouTube videos
“The world’s capacity to feed 9.5
promoting the basic concepts of soil health. Most
recently (early 2016), the USDA announced a further
billion people in 2050 in a context
139
funding increase of $70 million to NRCS for the
of climate change will depend in
delivery of even more soil health and nutrient
particular on our ability to keep
management strategies to U.S. farmers. This new
our soils alive”
funding is a direct result of the significant success that
the agency has realized working with farmers on the
– French Ministry of Agriculture,
ground, including the two U.S. farmers profiled in the
previous section.
Agrifood, and Forestry
PUTTING SOIL HEALTH FIRST
29
The NRCS websiteviii contains a wealth of information on
everything related to soil health, from the basics of soil biology to
details on how to implement best management practices.
France
The French Ministry of Agriculture, Agrifood, and Forestry has
recently become an outspoken champion of soil health,
particularly as expressed in higher levels of soil organic matter,
stating that the world’s “capacity to feed 9.5 billion people in
2050 in a context of climate change will depend in particular on
White fungal mycellium surrounding a leaf.
our ability to keep our soils alive”.140 The 4/1000 Initiative is a
voluntary action plan, sponsored and promoted by the French
Source: Y. Kries. 2016, Global Soil Biodiversity
Atlas. European Commission, Publications Office of
141
government. Its goal is to obtain commitments from other
the European Union, Luxembourg.
governments, international organizations, research institutions
and universities, agricultural organizations, civil society and the private sector to promote practices that
increase soil carbon.142
The name of the initiative was chosen because scientists have calculated that an annual growth rate in soil
carbon stocks of 0.4 per cent “would make it possible to stop the present increase in atmospheric CO 2.”143,144
This is not to say that the initiative necessarily believes that this is an achievable goal; rather, the intent is to
show that even a modest increase in soil carbon could have a significant effect. Stakeholders who sign on to
the initiative are expected to commit together to a voluntary action plan to: implement BMPs that sequester
carbon on as many agricultural sites as possible; work to preserve carbon-rich soils;145 and financially support
an international research program focusing on soil health and carbon sequestration in soils.146 As of August
2016, 33 countries and/or regions had signed on. Neither Canada nor Ontario are among these political
signatories, nor are any of Ontario’s agricultural organizations.147
The Climate Adaptation and Mitigation Potential of Soil Health for Ontario
Adaptation
If we consider the theory and practices of soil health in combination with the increasing number of success
stories, it becomes clear that this approach offers significant benefits to Ontario in terms of our ability to adapt
to a changing climate. We know that climate change will bring more extreme weather events to Ontario, with
more intense precipitation. The ability of soils to absorb and hold much larger quantities of rain water is crucial
to preparing for a number of climate-related risks, including increased flooding, soil erosion, water pollution,
and drought. In addition, covered soils are less susceptible to damage from extreme temperatures and
weather events.148 If most Ontario farms were managed in the way that leading soil health practitioners
viii
See: http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
30
ENVIRONMENTAL COMMISSIONER OF ONTARIO
manage their land, we could all breathe a lot easier with
respect to issues such as water quality and food
security.
The ECO is encouraged by the
recent announcement of a new
soil monitoring laboratory at the
Elora Research Farm.
One of the remaining obstacles is the shortage of peerreviewed, scientific studies that would supply the
credible, documented evidence of the practical benefits of soil health. Some of this research has been done in
Ontario,149,150 but more is needed. The ECO is encouraged by the recent announcement of a new soil
monitoring laboratory at the Elora Research Farm. The lab will be undertaking a comparison of two cropping
systems: a conventional corn-soy rotation; and another system called perennially enhanced rotation (PER),
where winter wheat is included along with cover crops and intercrops, in order to keep the ground covered
with green vegetation for as much of the year as possible. ix, 151
Mitigation
The ECO has written before on the potential for soils to sequester enough carbon to have a significant impact
on GHG emissions.x In 2011, we concluded, based on our own analysis, that a combination of recommended
management practices, such as cover crops, conservation tillage, and crop rotations, could provide the
province with almost ten per cent of the GHG reductions needed to meet Ontario’s 2020 target, or 2.9 Mt of
CO2e per year. This figure assumed take-up of these practices on 40 per cent of the province’s cropland and
a rate of sequestration of 2 tonnes of CO2e per hectare per year. The 2-tonne/hectare target is considered
ambitious by some soil scientists; however, similar (or even higher) figures have been documented by a
number of credible sources and the science on this subject is rapidly evolving.xi, 152
However, the difficulties with accurately measuring soil-carbon sequestration rates (both potential and actual)
are many. This is probably one of the major reasons why Ontario does not yet include soil carbon storage in its
long-term GHG mitigation planning. The possibility of future reversal is also a major concern, because carbon
held in soils can very easily be released if management practices change (e.g., tilling is resumed). The ECO
acknowledges these difficulties. However, the potential for GHG reductions through sequestering carbon in
our agricultural soils is real and significant,153 even if it is difficult to quantify and hard to ensure over the long
The Elora Research Farm is one of five research sites in Ontario. Some very important research work has already been
done at these sites on the benefits of various BMPs. The ECO believes that the new program is a step forward because
it will evaluate cropping systems, as opposed to individual BMPs.
ix
x
In particular, see “Soil Carbon Opportunities,” Section 4.3 of our 2011 GHG Report, and “The Roots of Sustainability:
Engaging the Soil Carbon Solution,” Section 6.2 of our 2010/2011 Annual Report.
The International Panel on Climate Change (IPCC) estimates the potential annual rate for carbon sequestration in
croplands to be between 1.1 and 1.8 tonnes of CO2e per hectare, and a 2007 study on the potential for Canadian
agriculture put the estimates even lower. However, recent scientific work has thrown new light on the mechanisms by
which soil sequesters carbon, and this new view suggests that the models used for the above estimates may be
generating figures that are too low, mainly because they do not take into account the activities of the soil food web (in
particular, the ability to “hide” carbon in aggregates).
xi
PUTTING SOIL HEALTH FIRST
31
term. The ECO believes that it is worth making the effort to
overcome these problems and develop protocols that can be used
both to measure progress and, eventually, support financial
incentive programs.
As an example of this potential, consider the benefit accrued from
just one farm over the past 25 years. The Belans (see pp. 24-25)
have been measuring the organic matter in their soils since they
moved away from tillage in 1991. The average soil organic matter
Mycorrhizal Structure in soil (extremely
important for good soil aggregation)
levels on their land have risen by about three per cent, from about
two per cent to about five per cent. Soil organic matter is about 60
Source: Soil and Water Conservation Society
(SWCS). 2000. Soil Biology Primer. Rev. ed.
per cent soil organic carbon, so the increase in soil carbon over
Ankeny, IA: Soil and Water Conservation Society.
that time is about 1.8 per cent (i.e., 60 per cent of 3). This
represents about 32.4 tonnes of additional carbon per hectare,xii
which is equivalent to about 119 tonnes of CO2e per hectare (one tonne of soil organic carbon = 3.67 tonnes
CO2e). Therefore, in total they have sequestered around 48,000 tonnes of CO2e in the top 15 centimeters of
their 405 hectares of soil since changing their approach to farming.
At this point, the reader should note that the ECO is not
suggesting that the Belan’s situation should be taken as
definitive from a soil-carbon sequestration perspective.
Although their measurements were done by accredited
soil labs, they did not follow any specific soil-carbon
sequestration protocols as to depth of the soil profile or
location of sampling, and the figures only represent an
estimate of what has happened in the top 15
centimeters of their soils. However, 25 years is long enough that the tillage practices employed have had
sufficient time to effect change, enhancing the likely accuracy of the estimate. In addition, the cover cropping,
adopted only recently, has not been practiced long enough to have had much of an impact on organic matter
levels. The latter point suggests that considerably more sequestration may be possible.
The Belans have sequestered
around 48,000 tonnes of CO2e in
the top 15 centimeters of their 405
hectares of soil since changing
their approach to farming.
The data suggest a soil-carbon sequestration rate of about 4.75 tonnes of CO2e/hectare/year, which is more
than twice the rate of 2 tonnes CO2e/hectare/year the ECO used in our 2011 analysis. Perhaps most
importantly, the Belans provide a useful example of what can be accomplished by the average Ontario farmer.
This assumes a sampling depth of 15 centimetres (cm), which is typical for Ontario soil testing, and a soil bulk density
of 1.2 grams/cm3 – the bulk density of an average soil with a reasonable amount of organic matter. If a depth of 30 cm or
more were used, the sequestration rate could change, depending on the carbon levels in the lower levels of soil.
xii
32
ENVIRONMENTAL COMMISSIONER OF ONTARIO
Table 1 compares the Belans’ data with the 4/1000 Initiative’s aspirational rate of 0.4 per cent of existing
carbon and puts both rates in the perspective of their potential for impacting Ontario’s GHG reduction targets.
Again, the ECO does not mean to suggest these numbers should be taken as the basis for future planning
purposes. Like the title of the 4/1000 Initiative, this is meant more to inspire and motivate than to set actual
targets. Nevertheless, the ECO believes that it is fair to say that the data suggest significant potential for soil
carbon sequestration in Ontario. For instance, the Belan numbers suggest that 40 per cent of cropland,
managed for soil health, has at least the potential to sequester enough carbon to meet 12.5 per cent of the
gap between current GHG emissions and the target for 2030.
Table 1 also shows that the Belan’s average increase in soil organic carbon over the past 25 years is about
9.5 times the rate proposed by the 4/1000 Initiative. Accordingly, even if the Belan’s carbon storage numbers
prove to be an overestimation, or an outlier, the data suggest that the 4/1000 Initiative is not promoting a
program based on an unachievable or unrealistic number, something out of reach by the average land
manager. An achievement of this level of sequestration over 90 per cent of Ontario’s farmland would reduce
the 2030 gap by 3 per cent – a worthwhile accomplishment, particularly when viewed in light of all the other
benefits that would accrue.
Table 1: Comparison of the GHG Reduction Impacts of Two Soil Carbon Sequestration Rates
NOTE: Number of hectares of Ontario cropland = 3,600,000; 2030 target + 115 MtCO2e/yr; Gap: 55
MtCO2e
**This is a rough estimate of the rate of C sequestration promoted by the 4 per 1000 Initiative
(converted into tCO2e/ha/yr). Since the 0.4 per cent figure represents an increase in existing stocks
(rather than an absolute increase), the rate will vary from place to place depending on the starting soil
carbon level.
PUTTING SOIL HEALTH FIRST
33
From Champions to a New Normal
Scientists have identified many advantages for farmers associated with soil health (and continue to do so).
Moreover, these findings are being corroborated by a growing number of farmers (as shown in the successful
case studies above) and policies in leading jurisdictions, such as the U.S. and France, are evolving rapidly to
reflect this emerging consensus.
This is all very good news. By putting soil health first, farmers can build on agriculture’s amazingly successful
modern history by addressing head-on the environmental shadow that has always been nagging at the edges
of their accomplishments. They can help their own bottom line and reduce their risk, while at the same time
playing a major role in addressing the sustainability issues facing humanity, from plummeting levels of
biodiversity to a changing climate. Adopting a soil health focus is not simply an interesting option for Ontario’s
farmers; it is at once an economic opportunity and an environmental imperative.
It won’t be easy, however. Conventional agriculture has worked very well from the perspective of the individual
farmer, in part because its practices are relatively simple to execute. In contrast, a soil health approach
requires greater effort by growers in terms of planning, monitoring, and managing complex rotations that often
include cover or secondary crops with no obvious markets. Effectively managing disease and pest issues are
another major concern when shifting to a new approach.
Furthermore, a strong culture has grown up around conventional agriculture. Clean, weed-free fields with
green crops clearly highlighted against dark earth are the well-respected norm. By comparison, fields where
the soil is never visible, always covered by residues and/or multi-species cover crops, may appear messy and
chaotic. Some soil health BMPs, such as no-till and cover cropping, were not held in high esteem by previous
generation of farmers. In terms of practical applications of the principles and BMPs of the soil health approach,
technical questions still abound.154
A soil health focus requires a farmer to tolerate more uncertainty, with no one to backstop the risk. Risk
management is a crucial issue for farmers; their livelihoods depend on being able to harvest an adequate yield
each year. We don’t blame farmers for wanting to minimize their risks and maximize their chances for
success.155 Current crop insurance programs don’t protect or support farmers who experiment with soil
health, even though it can take three years or more to see the benefits from a soil health focus. Soil-health
measurement techniques have not yet developed to the same point as chemical soil tests.156 With the latter,
nutrient requirements, for instance, are easy to assess and straightforward to address. Soil-health
assessments,157 on the other hand, are usually measurements related to soil characteristics, such as infiltration
rates for rainfall, and any prescriptions that result from these tests may be more qualitative than quantitative
(e.g., reduce tillage).158,159 From this perspective, it is easy to see why farmers might ask “How do I know for
sure that this will work for me?”, or “If it’s not broken, why fix it?”
34
ENVIRONMENTAL COMMISSIONER OF ONTARIO
On top of all this, the commercial network that
Building a wide-scale, soil health
supplies Ontario agriculture with inputs will have
focus in Ontario agriculture cannot be
significant adjustments to make. Conventional
done overnight. Farmers have every
agriculture depends on synthetic fertilizers for
nutrition and pesticides for crop protection. Since
right to be skeptical about moving
these inputs can cause some damage to the
away from a system that has been so
creatures of the soil food web (see “Throwing Sand
successful for them and their families.
in the Gears,” p.19), soil health practitioners use
them sparingly and carefully. This de-emphasis on
traditional inputs is likely to reduce demand for these products, while increasing demand for others (e.g., cover
crop seed, various inoculants, compost). This change will undoubtedly create some economic disruption as
product suppliers and crop advisors work to adapt. As mentioned above (see p. 19), some major suppliers
are already working on developing new products that are more in line with the soil-health approach.160
Developing these new and effective products will take time, however, and getting through the transition period
will be challenging for the agriculture industry as a whole.
An Important Role for the OMAFRA
Building a wide-scale, soil health focus in Ontario agriculture cannot be done overnight. Farmers have every
right to be skeptical about moving away from a system that has been so successful for them and their families.
They also have a right to expect solid evidence and successful role models, with appropriate support for
financial risk as they experiment with these new ideas
The OMAFRA should make the soil health “entrance ramp” for farmers as wide, accessible, and low-risk as
possible. The OMAFRA should take on a leading role in the following areas:
-
Address doubts and get wide buy-in, via research, demonstration projects, champions, and social
marketing campaigns. As discussed above, changing a culture is not easy. The ECO recommended in
our 2013/2014 Annual Report that the OMAFRA “identify Ontario’s leaders in soil health and
systematically integrate their key success factors in the ministry’s farm educational materials and research
priorities.” The ministry has started to do this by having local soil health practitioners speak at a growing
number of soil health workshops being held in Ontario (organized by both the OMAFRA and various
farming organizations) and by increasing the amount of research being done in the area of soil health.
However, much remains to be done in this area.
PUTTING SOIL HEALTH FIRST
35
-
-
-
-
Help farmers to manage transition risks, via potential changes to
The OMAFRA’s Soil-Health
crop insurance rules, removing disincentives and replacing them
Initiative
with incentives to drive change, and funding innovation in research
In December, 2014, the ECO received
and in the field. This is a very important area that has not yet been
an Application for Review from two
addressed by the government. However, in response to an
Ontario citizens, asking for a review of
the need for a comprehensive “soilapplication for review by two Ontario citizens concerned about the
care” policy and regulatory framework
health of Ontario’s soils, the ministry has launched a soil health
in Ontario. The ECO sent this
initiative (see “The OMAFRA’s Soil Health Initiative,” at right), which
application to the OMAFRA, the
the ECO is hopeful will address these concerns. In addition, the
Ministry of the Environment and
Ministry of the Environment and Climate Change recently released
Climate Change, and the Ministry of
Municipal Affairs and Housing. The
its Five Year Climate Change Action Plan, which identifies
OMAFRA agreed to conduct this
intended Greenhouse Gas Reduction Account funding of $30
review and the other two ministries
million to support long-term soil health.161
agreed to lend support. This review is
Resolve technical issues. Specifically, farmers need better
currently in progress. In the interim,
the ECO has learned from briefings
methods for measuring carbon and soil health that are quick and
162 ,xiii
with the OMAFRA that the ministry
inexpensive.
Once these have been developed, government
has adopted soil health as a high
could employ citizen scientists (farmers and other soil managers)
priority and has created a multito collect the baseline data needed to launch new programs, as
stakeholder advisory group to provide
well as to monitor their progress and success.
a wide range of expert input. The first
results of this consultation were
Manage the “disruptive innovation” that defines the soil-health
posted on the Environmental Registry
approach. This area of activity should include dealing with issues
on August 29, 2016, in the form of an
such as: industry sectors that may lose business; the need to
initial discussion document for
retrain professionals; dealing with land ownership issues; and
developing a Soil Health and
Conservation Strategy for Ontario,
bringing existing laws like the Drainage Act, the Endangered
titled Sustaining Ontario’s Agricultural
Species Act, and the Nutrient Management Act into sync with the
Soils: Towards a Shared Vision.
new vision of agriculture.
Promote the concept of a level playing field. More generally, the OMAFRA should champion the concept
of a level playing field for a sustainable economy and how that applies to agriculture in general and soil
health in particular. This concept incorporates issues such as full-cost accounting, where the ecological
costs and benefits of an activity are considered on an equal footing with the standard economic
parameters. For instance, the costs of planting cover crops are borne by the individual farmer, while many
of the benefits are enjoyed by society at large, via reduced pollution. Farmers who do not employ cover
crops do not incur these additional costs; a level playing field would involve some mechanism for
recognizing the societal benefits provided by BMPs, so that the practitioners are not punished
economically for doing the right thing.
xiii
The OMAFRA has been working to develop a soil health assessment protocol by testing the Cornell Soil Health
Assessment test and adapting it to the Ontario context. This work is still in progress.
36
ENVIRONMENTAL COMMISSIONER OF ONTARIO
The Potential of Carbon Offsets in Agriculture
The use of carbon offsets to incentivize increases in soil carbon,163,164 while at first glance attractive, includes
some major pitfalls. As discussed above, increases in soil carbon levels are difficult and costly to measure,
and perhaps most significantly, these increases can be quickly and easily reversed by abandoning the
practices that created them in the first place. This does not mean that as a society we should not find ways to
promote, or even reward, soil carbon sequestration;xiv, 165 rather, it means that direct offset payments to
farmers for sequestering carbon may not be the best way to achieve the overall goal of healthier soils.
One useful direction with respect to the use of offsets may involve taking a different focus. Instead of
rewarding carbon storage in soils, some organizations are employing a protocol for reduction in fertilizer use.
As stated above, 43 per cent of Ontario agriculture’s GHGs come from the application of synthetic fertilizers
and raw manures. As demonstrated by existing soil-health practitioners, farmers adopting this approach could
gradually reduce their need for synthetic nitrogen fertilizer. In fact, several fertilizer protocols have already been
developed in the U.S.; three of them are based strictly on reduced application rates,166 while the other also
includes factors such as form, timing, and placement of the fertilizer.167 They are all used for corn crops in the
U.S., but could be adapted to other regions and crops.
The ECO believes that this approach has potential for reducing GHG emissions from soils. The provision of
offsets for certain reductions could help farmers who have adopted soil-health practices take that risky but
important next step of reducing fertilizer inputs. Even after implementing a number of soil health best
management practices, farmers may be understandably worried about reducing the recommended levels of
synthetic fertilizers, uncertain whether the increased natural fertility of their soils will be enough to maintain
yield. Offsets could help in that regard, especially if they were accompanied by other support mechanisms,
such as appropriately modified crop insurance programs.
xiv
In fact, the USDA recently awarded a U.S. $1,000,000 grant to the National Corn Growers Association to “develop a
system for scalable carbon accounting in agriculture, to be developed through its Soil Health Partnership Initiative.”
PUTTING SOIL HEALTH FIRST
37
ECO Comment and Recommendations
Comment
The climate change potential in healthy soils is
enormous, but if the soil health movement is to fully
take hold in a timely manner in Ontario, government
must play a substantive and proactive role.
Soil health is not something that you
can just “add on” to an existing
system of soil management
The most significant challenge to this initiative arises
from the fact that soil health is not something that you can just “add on” to an existing system of soil
management. It requires a different approach that puts the primary focus on protecting and enhancing the life
in the soil. This approach requires a deep appreciation and technical understanding of soil life, and how largely
invisible creatures, in tandem with photosynthesis, pull carbon out of the atmosphere, mitigating climate
change, and then use it to build and maintain the resiliency needed for effective adaptation. Soil health, and
the soil food web that provides it, cannot be an afterthought; it must be the first thought.
A province-wide conversion to a soil health approach will take time, effort and resources by government. It will
require significant efforts in the areas of focused research, targeted technical assistance, appropriate riskmanagement programs, effective and easily accessible education, and workable incentives.168 Most of all,
however, it will require a profound commitment on the part of government, to understand the nature and value
of the changes required and of the challenges involved, and to making the necessary changes happen.
38
ENVIRONMENTAL COMMISSIONER OF ONTARIO
Recommendations
First, the ECO recommends that the province of Ontario sign up to the 4/1000 Initiative. Encouraging a
conversion to a soil health focused approach to agriculture will be easier if we work with other jurisdictions that
are on the same path.169 We also encourage the OMAFRA to recommend membership in this initiative to the
various appropriate civil society organizations, such as the Ontario Federation of Agriculture and the Ontario
Soil and Crop Improvement Association.
Second, the ECO recommends that the OMAFRA:
-
co-ordinate the development of a protocol, with supporting methods and technologies, for reliably
estimating soil-carbon levels in Ontario; and
implement a program for estimating soil-carbon levels across the province every three years, and making
these results public.
Third, the ECO recommends that the Ontario government find a way to link the cost of crop insurance to soilcarbon levels in recognition that high-carbon soils reduce risks to crops.
And fourth, the ECO recommends that the province develop a program to provide financial support for up to
10 years for farmers who adopt soil health best management practices, designed to offset any yield loss due
to transition issues. This program could potentially employ carbon offsets, such as those that reward reduced
fertilizer use, as part of the financial support framework.
PUTTING SOIL HEALTH FIRST
39
Endnotes
Simpson, Sarah. Scientific American. Nitrogen Fertilizer: Agricultural Breakthrough – And Environmental Bane. March, 2009.
Health Canada. GM Foods and their Regulation. http://www.hc-sc.gc.ca/fn-an/gmf-agm/fs-if/gm-foods-aliments-gm-eng.php
3
Statistics Canada. Human Activity and the Environment, Pub. 16-201-X. Section 1: Food in Canada. Chart 1.1.
4
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Historical Provincial Estimates by Crop, 1981-2014.
http://www.omafra.gov.on.ca/english/stats/crops/estimate_hist_imp.htm
5
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Historical Provincial Estimates by Crop, 1981-2014.
http://www.omafra.gov.on.ca/english/stats/crops/estimate_hist_imp.htm
6
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Estimated Area, Yield, Production and Farm Value of Specified Field
Crops, Ontario, 2011-2015 (Imperial and Metric Units). http://www.omafra.gov.on.ca/english/stats/crops/estimate_new.htm
7
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Historical Provincial Estimates by Crop, 1981-2014.
http://www.omafra.gov.on.ca/english/stats/crops/estimate_hist_imp.htm
8
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Estimated Area, Yield, Production and Farm Value of Specified Field
Crops, Ontario, 2011-2015 (Imperial and Metric Units). http://www.omafra.gov.on.ca/english/stats/crops/estimate_new.htm
9
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Historical Provincial Estimates by Crop, 1981-2014.
http://www.omafra.gov.on.ca/english/stats/crops/estimate_hist_imp.htm
10
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Estimated Area, Yield, Production and Farm Value of Specified Field
Crops, Ontario, 2011-2015 (Imperial and Metric Units). http://www.omafra.gov.on.ca/english/stats/crops/estimate_new.htm
11
Statistics Canada. 2011 Farm and Farm Operator Data: Snapshot of Canadian Agriculture: Chapter 1.
http://www.statcan.gc.ca/pub/95-640-x/2011001/p1/p1-01-eng.htm
12
Environment and Climate Change Canada. Canada’s Greenhouse Gas Inventory. March, 2016. https://www.ec.gc.ca/gesghg/default.asp?lang=En&n=83A34A7A-1
13
As communicated to the ECO by Environment Canada.
14
Agriculture and Agrifood Canada. Environmental Sustainability of Canadian Agriculture – Agri Environmental Report Series – Report
#4. 2016, p. 94.
15
Environment and Climate Change Canada. Canada’s Greenhouse Gas Inventory. March, 2016. https://www.ec.gc.ca/gesghg/default.asp?lang=En&n=83A34A7A-1
16
Food and Agriculture Organization (FAO). Trade Reforms and Food Security. Chapter 2: “Food Security: Concepts and
Measurement.”
17
Gunderson, Lance H. Annu. Rev. Ecol. Syst., 31. Ecological Resilience – in Theory and Application, pp. 425-39. 2000.
18
United States Environmental Protection Association (US EPA). Climate Change Impacts on Agriculture and Food Supply.
https://www3.epa.gov/climatechange/impacts/agriculture.html
19
Ontario Centre for Climate Impacts and Adaptation Resources (OCCIAR). Agriculture: in a changing climate. www.climateontario.ca
20
Schlenker, Wolfram and Michael J. Roberts. PNAS. Vol. 106, no. 37. Nonlinear temperature effects indicate severe damages to
U.S. crop yields under climate change. September, 2009.
21
Ontario Centre for Climate Impacts and Adaptation Resources (OCCIAR). Agriculture: in a changing climate. www.climateontario.ca
22
Center for American Progress. Agriculture and the Paris Agreement. May 12, 2016.
23
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Role of Soil Organic Matter.
24
Bot, Alexandra and Jose Benites. 2005. “The importance of soil organic matter.” Food and Agriculture Organization of the United
Nations: FAO Soils Bulletin 80.
25
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Role of Soil Organic Matter.
http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
26
United States Environmental Protection Association (US EPA). Climate Change Impacts on Agriculture and Food Supply.
https://www3.epa.gov/climatechange/impacts/agriculture.html
27
Penn State Extension. Managing Phosphorus for Agriculture and the Environment. http://extension.psu.edu/plants/nutrientmanagement/educational/soil-fertility/managing-phosphorus-for-agriculture-and-the-environment
28
Dirzo et al. Science 25. Defaunation in the Anthropocene. pp. 401-406. July, 2014.
29
Schwagerl, Christian. Yale Environment 360. Vanishing Act: Why Insects Are Declining and Why It Matters. 6 Jul, 2016.
30
For a fairly detailed analysis of the problems associated with intensive or “industrial agriculture,” see the following report: International
Panel of Experts on Sustainable Food Systems (IPES-Food). From Uniformity to Diversity: a paradigm shift from industrial agriculture to
diversified agroecological systems. June, 2016. www.ipes-food.org.
1
2
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
Don McCabe, personal communication: buffer strips are ineffective because most P is lost in winter and early spring when the strips
are frozen and the P-laden water runs right over them.
32
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Video on Soil Health Principles,
featuring NRCS spokesperson Ray Archuleta. From minute 9:30 on, Archuleta describes how buffers are “diapers” and not a real
solution to the problem of nutrient and water loss.
33
The information in Footnote 4 was provided by Charles Lalonde and Don McCabe of the Ontario Federation of Agriculture (OFA).
34
Cernansky, Rachel. 2016. Secrets of life in the soil. Nature/News Feature. 13 September, 2016.
35
Stika, Jon. A Soil Owner’s Manual. Introduction. 2016.
36
Clapperton, Jill. Rhizoterra Inc. Slide presentation - Soil Health Principles. 2014. www.rhizoterra.com
37
New research suggests that the flow of carbon through plants to underground ecosystems may be crucial to how the environment
responds to climate change – See: Bardgett, Richard D. The Scientist. The Root of the Problem. August 1, 2011.
38
Clapperton, Jill. Rhizoterra Inc. Healthy Soil is the Foundation of Civilizations. www.rhizoterra.com
39
Orgiazzi, A., Bardgett, R.D., Barrios, E., Behan-Pelletier, V., Briones, M.J.I., Chotte, J-L., De Deyn, G.B., Eggleton, P., Fierer, N.,
Fraser, T., Hedlund, K., Jeffery, S., Johnson, N.C., Jones, A., Kandeler, E., Kaneko, N., Lavelle, P., Lemanceau, P., Miko, L.,
Montanarella, L., Moreira, F.M.S., Ramirez, K.S., Scheu, S., Singh, B.K., Six, J., van der Putten, W.H., Wall, D.H. (Eds.). European
Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity Atlas. 2016. Page 9.
40
Kibblewhite, M.G., K. Ritz and M.J. Swift. Phil. Trans. R. Soc., 363: 685-701. Soil Health in Agricultural Systems. 2008.
41
Orgiazzi, et al. European Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity Atlas,
Chapter 1 – the Soil Habitat. 2016.
42
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Soil Health Nuggets.
http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
43
Damrosch, Barbara. Washington Post. ‘Symphony of the Soil’ examines the fascinating world below your feet. October 2, 2013.
44
Orgiazzi, A. et al. European Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity Atlas.
Page 169. 2016.
45
Wardle, David et al. 2004. Science, vol. 304. Ecological Linkages between Aboveground and Belowground Biota. June 11, 2004.
46
Townsend, Lee, Potter, Dan, and Powell, A.J. University of Kentucky Cooperative Extension Service, College of Agriculture.
Earthworms: Thatch-Busters.
47
Wall, Diana H., Uffe N. Nielsen, and Johan Six. Soil biodiversity and human health. Nature, Vol 000. 2015.
48
Orgiazzi, A. et al. European Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity Atlas.
Page 93. 2016.
49
Stika, Jon. A Soil Owner’s Manual, p. 26. 2016.
50
For more detailed discussions of this specific benefit, see: “The Roots of Sustainability: Engaging the Soil Carbon Solution”, Section
6.2 of the ECO’s 2010/2011 Annual Report, entitled Engaging Solutions; and Section 3.2.5 of the ECO’s 2014 Climate Change
Report: Looking for Leadership
51
Magdoff, Fred and Harold Van Es. Sustainable Agriculture Research and Education (SARE) Program. Building Soils for Better Crops.
3rd Edition. Handbook Series Book 10, pp. 39-41. 2009.
52
Penn State Extension. Cooperative Extension, College of Agricultural Sciences. Introduction to Soils. Soil Quality. p. 2.
53
Nichols, Kris. USDA-ARS-Northern Great Plains Research Lab. Does Glomalin Hold Your Farm Together?
54
Rillig, Matthias C., Sara F. Wright and Valerie T. Eviner. Plant and Soil 238:325-333. The role of arbuscular mycorrhizal fungi and
glomalin in soil aggregation: comparing effects of five plant species. 2002.
55
Singh, Pradeep Kumar. 2012. Agricultural Science Research Journal. Vol 2(3). Role of Glomalin Related Soil Protein Produced by
Arbuscular Mycorrhizal Fungi: A Review. March, 2012.
56
Penn State Extension. Cooperative Extension, College of Agricultural Sciences. Introduction to Soils. Soil Quality. Pp. 3-4.
57
Murphy, B.W. 2014. Department of the Environment, Canberra, Australia. Soil Organic Matter and Soil Function – Review of the
Literature and Underlying Data, p. 34.
58
For a detailed discussion of how SOM holds water, and how much it can increase the water holding capacity of soils, see: Jones,
Christine. Managing Wholes.com, May 2. Soil Carbon means WATER to me! 2010.
59
Clapperton, Jill. Rhizoterra. Inc. Healthy Soil is the Foundation of Civilizations. 2014. www.rhizoterra.com
60
Orgiazzi, A., et al. (Eds.). European Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity
Atlas, p. 176 2016.
61
Cornell University. NRCCA Study Resources, Competency Area 2: Basic Concepts of Soil Fertility.
62
International Plant Nutrition Institute. Enviro-Brief # 01.
63
International Plant Nutrition Institute. Enviro-Brief # 01.
64
Ingham, Elaine R. Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Soil Food
Web. http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
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Magdoff, Fred and Harold Van Es. Sustainable Agriculture Research and Education (SARE) Program. Building Soils for Better Crops.
3rd Edition. Handbook Series Book 10, pp. 38-39. 2009.
66
Jill Clapperton. Video - Soil Health Principles. https://www.youtube.com/watch?v=-z-r30mKP3c
67
Bais et al. Annu. Rev. Plant Biol. 57. The Role of Root Exudates in Rhizosphere Interactions with Plants and Other Organisms. pp.
233-266. 2006.
68
Walker, Travis S., Harsh Pal Bais, Erich Grotewold, and Jorge M. Vivanco. Plant Physiol. Vol 132. Root Exudation and Rhizosphere
Biology. pp. 44-51. 2003.
69
Clapperton, Jill. Rhizoterra Inc. Healthy Soil is the Foundation of Civilizations. www.rhizoterra.com
70
Nguyen, C. Agronomie 23, as referenced by Patrick Lavelle on p. 11 of Chapter 1.1 of Soil Ecology and Ecosystem Services, Diana
Wall, ed. Oxford University Press. 2003.
71
Bais et al. Annu. Rev. Plant Biol. 57:233-266. The Role of Root Exudates in Rhizosphere Interactions with Plants and Other
Organisms, p. 251. 2006.
72
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). Soil Biology Primer, Chapter on
Soil Fungi. http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
73
Magdoff, Fred and Harold Van Es. Building Soils for Better Crops. Handbook Series Book 10. Sustainable Agriculture Research and
Education (SARE) Program, 3rd Edition. pp. 39-41. 2009.
74
For a good explanation of the entire C cycle, as it pertains to soil-carbon sequestration, see: Kane, Daniel. National Sustainable
Agriculture Coalition. Carbon Sequestration Potential on Agricultural Lands: A Review of Current Science and Available Practices.
2015.
75
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). The Food Web and Carbon
Sequestration. http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
76
A very important paper on soil carbon sequestration argues that new models are needed to predict levels of soil carbon
sequestration because it is what the authors call “an ecosystem property”, rather than simply a biological, chemical or physical
property. See: Schmidt et al. Nature, Vol 478. Persistence of soil organic matter as an ecosystem property. October, 2011. pp. 49-56.
77
Mycorrhizal fungi are particularly important to soil-carbon sequestration. See: Wilson et al. Ecology Letters, vol. 12: 452-461. Soil
aggregation and carbon sequestration are tightly correlated with the abundance of arbuscular mycorrhizal fungi: results from long-term
field experiments. 2009.
78
These principles are described in detail on the NRCS Webpage on Soil Health Management.
http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
79
Davis, Adam S., Jason D. Hill, Craig A. Chase, Ann M. Johanns, and Matt Liebman. PLOS|One, Vol 7, Issue 10. Increasing
Cropping System Diversity Balances Productivity, Profitability and Environmental Health. October, 2012.
80
Vukicevich, Eric, Tom Lowery, Pat Bowen, Jose Ramon Orbez-Torres, and Miranda Hart. Agron. Sustain. Dev. 36:48. Cover crops
to increase soil microbial diversity and mitigate decline in perennial agriculture. A review. 2016.
81
Jill Clapperton. Video - Soil Health Principles. https://www.youtube.com/watch?v=-z-r30mKP3c
82
Lancaster University. Science Daily, 27. Mix up plant species to keep soil healthy. July, 2016.
83
Mulhollem, Jeff. Penn State. First-of-kind study suggests cover crop mixtures increase agroecosystem services. September 7,
2016.
84
American Society of Agronomy. Science Daily. More for less in pastures. July 20, 2016.
85
For example, see: Basche et al. Agriculture Water Management. 172: 40-50. Soil water improvements with the long term use of a
winter rye cover crop. 2016.
86
Rillig, Matthias C. Can. J. Soil Sci. 84: 355-363. Arbuscular mycorrhizae, glomalin, and soil aggregation. 2004.
87
In fact, mycorrhizal fungi may be a key factor in the amount of carbon that a soil sequesters. Dr. Christine Jones, an Australian soil
ecologist, has held this view for several years and the latest science seems to support her position. See: Jones, Christine. Evergreen
Farming Newsletter. Mycorrhizal fungi – powerhouse of the soil. September, 2009.
88
Jones, Dr. Christine. From light to life: restoring farmland soils. 2016. www.amazingcarbon.com
89
Stika, Jon. A Soil Owner’s Manual. See Chapter 4.
90
Magdoff, Fred and Harold Van Es. Sustainable Agriculture Research and Education (SARE) Program. Building Soils for Better Crops.
3rd Edition. Handbook Series Book 10. p. 213. 2009.
91
Magdoff, Fred and Harold Van Es. Sustainable Agriculture Research and Education (SARE) Program. Building Soils for Better Crops.
3rd Edition. Handbook Series Book 10. p. 235. 2009.
92
Russel, Ann E., Cynthia A. Cambardella, David A. Laird, Dan B. Jaynes, and David W. Meek. Ecological Applications, 19(5). Nitrogen
fertilizer effects on soil carbon balances in Midwestern U.S. agricultural systems. 2009.
93
Hepperly, Paul. Pesticides and You, Vol. 27 (1). The Organic Farming Response to Climate Change. 2007.
94
Orgiazzi, A., et al. (Eds.). European Commission, Publications Office of the European Union, Luxembourg. Global Soil Biodiversity
Atlas, pp. 122-3. 2016.
65
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Townsend, Lee and Dan Potter. University of Kentucky – College of Agriculture. Entfact-402. Earthworms: Thatch-Busters.
Tsiafouli et al. Global Change Biology 21: 973-985. Intensive agriculture reduces soil biodiversity across Europe. 2015.
97
Beck, Dwayne. Dakota Lakes Reseach Farm, South Dakota State University. Managing Agricultural Ecosystems.
98
Top Crop Manager. Use integrated fertilizer and cropping systems to help manage weeds. Nov. 29, 1999.
http://www.topcropmanager.com/
99
Doornbos, Roger F., LeendertCornelis van Loon, and Peter A. H. M. Bakker. Agron. Sustain. Dev.32: 227-243. Impact of root
exudates and plant defense signaling on bacterial communities in the rhizosphere. A review. 2012.
100
Stika, Jon. A Soil Owner’s Manual. See p. 30.
101
Townsend, Lee and Dan Potter. University of Kentucky – College of Agriculture. Entfact-402. Earthworms: Thatch-Busters.
102
Sullivan, Preston. 2004. “Sustainable Management of Soil-Borne Plant Diseases.” National Centre for Appropriate Technology:
National Sustainable Agriculture Information Service (ATTRA).
103
Karlsson, Ida, Hanna Friberg, Christian Steinberg, and Paula Persson. 2014. “Fungicide Effects on Fungal Community Composition
in the Wheat Phyllosphere”. PLOS|one. November.
104
Kelley, Emily C. 2014. “NMSU researcher’s carbon sequestration work highlighted in ‘The Soil Will Save Us’”. New Mexico State
Newsletter, 07/08/14.
105
Wilson et al. 2009. “Soil aggregation and carbon sequestration are tightly correlated with the abundance of arbuscular mycorrhizal
fungi: results from long-term field experiments”. Ecology Letters, 12: 452-461.
106
Read, David J., Jonathon R. Leake, and Jesus Perez-Moreno. 2004. “Mycorrhizal fungi as drivers of ecosystem processes in
heathland and boreal forest biomes”. Can. J. Bot. 82: 1243-1263.
107
Johnson, David, Joe Ellington and Wesley Eaton. 2015. “Development of soil microbial communities for promoting sustainability in
agriculture and a global carbon fix.” PeerJ Preprints. | http://dx.doi.org/10.7287/peerj.preprints.789v1 | CC-BY 4.0 Open Access | rec:
13 Jan 2015, publ: 13 Jan 2015
108
Leifheit, Eva F. 2014. “Soil sustainability and arbuscular mycorrhizal fungi”. Inaugural-Dissertation. Freie Universitat Berlin.
109
Rinaudo, Valeria, Paolo Barberi, Manuela Giovannetti, Marcel G.A. van der Heijden. 2009. “Mycorrhizal fungi suppress aggressive
agricultural weeds”. Plant Soil, 333:7-20.
110
USDA. NRCS. Farming in the 21st Century.
111
USDA. NRCS. Grower checklist
112
Conant, Richard T., Mark Easter, Keith Paustain, Amy Swan, and Stephen Williams. Soil & Tillage Research 95. Impacts of periodic
tillage on soil C stocks: A synthesis. pp. 1-10. 2007.
113
Fisher, Madeline. Crops & Soils Magazine, American Society of Agronomy. Sod-based rotations. Sept-Oct, 2011.
114
Syngenta. 2016. Improving Soil Health and Choosing the Right Cover Crops Can Reduce Soybean Cyst Nematode.
115
Davis, Adam S., Jason D. Hill, Craig A. Chase, Ann M. Johanns, and Matt Liebman. PLOS|ONE 7(10). Increasing Cropping System
Diversity Balances Productivity, Profitability and Environmental Health. e47149. Doi:10.1371/journal.pone.0047149 . 2012.
116
Thierfelder, Christian and Patrick C. Wall. International maize and Wheat Improvement Centre (CIMMYT). The Importance of Crop
Rotations.
117
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Cover Crops: Adaptation and Use of Cover Crops.
http://www.omafra.gov.on.ca/english/crops/facts/cover_crops01/cover.htm
118
International Plant Nutrition Institute (IPNI). 4Rs of Nutrient Stewardship. http://www.nutrientstewardship.org/4rs
119
Hepperly, Paul, Don Lotter, Christine Ziegler Ulsh, Rita Seidel and Carolyn Reider. Compost Science & Utilization, Vol 17, No. 2,
117-126. Compost, Manure and Synthetic Fertilizer Influences Crop Yields, Soil Properties, Nitrate Leaching and Crop Nutrient
Content. 2009.
120
Leu, Andre. Organics and Soil Carbon: Increasing soil carbon, crop productivity and farm profitability. Presentation to Katanning
Workshop, March, 2007. www.amazingcarbon.com
121
“Once plants and animals were raised together on the same farm — which therefore neither produced unmanageable surpluses of
manure, to be wasted and to pollute the water supply, nor depended on such quantities of commercial fertilizer. The genius of
America’s farm experts is very well demonstrated here: they can take a solution and divide it neatly into two problems”. Berry, Wendell.
The Unsettling of America: Culture & Agriculture (1996), p. 62.
122
Agriculture and Agri-Food Canada, Victoria McPhail, Ontario Ministry of Agriculture, Food and Rural Affairs, and Jack Kyle. Rotational
Grazing in Extensive Pastures. A Best Management Practice (BMP) Guide. 2012.
123
Hamilton, Lisa S. The Atlantic. The Brown Revolution: Increasing Agricultural Productivity Naturally. September 29, 2011.
124
For a dramatic Ontario example of this statement, consider this case study: Islam, Rafiq, Dean C. Glenney, and George Lazarovits.
Agron. Sustain. Dev. 35: 837-846. No-till strip row farming using yearly maize-soybean rotation increases yield of maize by 75%. 2015.
125
Brown, Gabe. Keys to Building a Healthy Soil. One-hour presentation by Gabe Brown at a the Idaho Center for Sustainable
Agriculture’s annual symposium. 2014. https://www.youtube.com/watch?v=9yPjoh9YJMk
95
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Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Estimated Area, Yield, Production and Farm Value of Specified
Field Crops, Ontario, 2011-2015 (Imperial and Metric Units). http://www.omafra.gov.on.ca/english/stats/crops/estimate_new.htm
127
USDA/NASS 2015 State Agriculture Overview for New York State.
128
The information on the Martens’ farm is from a recorded webinar conducted by the Natural Resources Conservation Service
(NRCS), United States Department of Agriculture. The webinar can be found here:
http://www.conservationwebinars.net/webinars/managing-for-soil-health-on-an-organic-farm/?searchterm=None
129
Data provided by the St. Clair Conservation Authority.
130
St. Clair Region Soil and Crop News, Vol 2, Issue 1. Crops and Conservation. March, 2016.
131
Davis, Adam S., Jason D. Hill, Craig A. Chase, Ann M. Johanns, and Matt Liebman. PLOS|One, Vol 7, Issue 10. Increasing
Cropping System Diversity Balances Productivity, Profitability and Environmental health. October, 2012.
132
Knapp, Alex. Forbes. These Two Scientists Just Raised $4 Million to Test Soil Health For Farmers. July 13, 2016.
133
Biological controls use microbes to prevent disease or inhibit pests. Here is another example: Narisawa et al. Plant Dis. 89: 285290. Effects of Pathogen Density, Soil Moisture, and Soil pH on Biological Control of Clubroot in Chinese Cabbage by Heteroconium
chaetospira. 2005.
134
Krotz, Dan. Berkley Lab Newsletter. It Takes a Community of Soil Microbes to Protect Plants From Disease. May 5, 2011.
135
Pearce, Ralph. Country Guide. Enhancing the biotechnology of crops with microbials. Nov. 12, 2015.
136
Zhang, Sarah. Genetic Literacy Project. Pesticides, fertilizers derived from microbes offer new frontier in agriculture. March 22,
2016.
137
Agricultural companies are also partnering with environmental organizations to support soil health initiatives. See: Enoch, Daniel.
Agri-Pulse. Companies, green groups partner for soil health. August 31, 2016.
138
Natural Resources Conservation Service (NRCS), United States Department of Agriculture (USDA). 80 Years Helping People Help
the Land: A Brief History of NRCS. http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
139
United States Department of Agriculture (USDA). News Release # 0112.16. Agriculture Secretary Vilsack Announces Climate Smart
Agriculture and Forestry Results, Additional $72.3 Million Soil Health Investment to Support Paris Agreement. May 12, 2016.
140
Ministere de L’agriculture de L’Agroalimentaire et de la Foret. Join the 4/1000 initiative, p. 2. 2015.
http://newsroom.unfccc.int/media/408539/4-per-1000-initiative.pdf
141
Ministere de L’agriculture de L’Agroalimentaire et de la Foret. Join the 4/1000 initiative, p. 2. 2015.
http://newsroom.unfccc.int/media/408539/4-per-1000-initiative.pdf
142
Ministere de L’agriculture de L’Agroalimentaire et de la Foret. Join the 4/1000 initiative, p. 2. 2015.
http://newsroom.unfccc.int/media/408539/4-per-1000-initiative.pdf
143
For a good discussion as to how this initiative is supposed to work and whether it is possible, see: Koch, Andrea et al. Global Policy
Journal. 4/1000 – Soil Carbon to Mitigate Climate Change.
144
See also: Gustin, Georgina. Inside Climate News. Looking to the Earth Itself as a Climate Solution. September, 2016.
145
Ministere de L’agriculture de L’Agroalimentaire et de la Foret. Join the 4/1000 initiative, p. 3. 2015.
http://newsroom.unfccc.int/media/408539/4-per-1000-initiative.pdf
146
Ministere de L’agriculture de L’Agroalimentaire et de la Foret. Join the 4/1000 initiative, pp. 3-5. 2015.
http://newsroom.unfccc.int/media/408539/4-per-1000-initiative.pdf
147
See list of 4/1000 partners at this site: http://4p1000.org/partners
148
Basche, Andrea D. et al. Agricultural Water Management 172: 40-50. Soil water improvements with the long-term use of a winter
rye cover crop. 2016.
149
Congreves, K. A., A. Hayes, E.A. Verhallen, L.L. Van Eerd. Soil & Tillage research, 152: 17-28. Long-term impact of tillage and crop
rotation on soil health at four temperate agroecosystems. 2015.
150
Van Eerd, Laura L, Katelyn A. Congreves, Adam Hayes, Anne Verhallen, and David. C. Hooker. Can. J. Soil Sci. 94: 303-315.
Long-term tillage and crop rotation effects on soil quality, organic carbon, and total nitrogen. 2014.
151
Ontario Soil and Crop Improvement Association (OSCIA). Healthy Soil Research First of Kind in North America. 2016.
http://www.ontariosoilcrop.org/blog/2016/07/26/healthy-soil-research-first-of-kind-in-north-america/
152
The rate at which agricultural soils can sequester carbon is an important factor. The estimates developed by the International Panel
on Climate Change (IPCC) are in the range of 1.1 to 1.8 tonnes of CO2e per hectare per year. A study done in 2007 on the potential for
Canadian agriculture put the figures for central Canada somewhat lower: 0.36 tCO2e/ha/yr (for change from conventional tillage to notill); and 1.1 tCO2e/ha/yr (for decreasing the use of summer fallow). Do these figures imply that the higher rates of soil-carbon
acquisition measured by soil-health practitioners like Mike Belan and Gabe Brown (4.5 tCO2e/ha/yr and up) are inaccurate, or are they
outliers? This is a matter of some debate and the ECO cannot state a definitive answer at this point in time. However, recent scientific
evidence seems to support the view that the established estimates of potential are too low and the higher numbers for soil carbon
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ENVIRONMENTAL COMMISSIONER OF ONTARIO
sequestration found increasingly in the literature and the media may indeed represent a better expression of the potential of soil to
capture carbon. The key to this discussion is an understanding of how the existing models for estimating carbon sequestration are
designed. see: Kane, Daniel. National Sustainable Agriculture Coalition. Carbon Sequestration Potential on Agricultural Lands: A
Review of Current Science and Available Practices. November, 2015.
153
Li, Xiaomei and Yongsheng Feng. Alberta Research Council. Carbon Sequestration Potentials in Agricultural Soils. www.arc.ab.ca
154
For an interesting discussion of farming attitudes, read: Pearce, Ralph. Country Guide. Learning from organic agriculture. May 9,
2016.
155
For an interesting discussion on the topic of changing cultures and risk, see: Wilson, Mike. Farm Futures. Soil health just needs
one first step. June 1, 2016.
156
See the following document for an example of how one group of land managers in Australia have formed a cooperative to “better
understand and manage for soil biological health”: Mudgee Microscope Group. Beyond the Rhetoric. A Case Study: A cooperative
approach by land managers to better understand and manage for soil health. www.watershedlandcare.com.au.
157
There have been a number of tests developed in recent years to provide the farmer with at least a general idea of soil health. See
this article in Country Guide for a general discussion of one of these tests: Pearce, Ralph. 2016. “A healthier soil test”. In Country
Guide, Sept. 8.
158
For a good example of soil-health testing and assessment methods, see: Al-Kaisi, Mahdi and David Kwaw-Mensah. Iowa Soil
Health Management Manual. Iowa State University, Extension and Outreach, with funding from NRCS. pp. 29-32. 2016.
159
A new soil health test is being offered in Ontario, as of 2016. It is called the “SoilOne Report”. See: Pearce, Ralph. Country Guide.
Getting down to biology. August 22, 2016.
160
De Vries, Jop. Science, Vol. 349, Issue 6249. The Littlest Farmhands. pp. 680-683. 2015.
161
Province of Ontario. Ontario’s Five Year Climate Change Action Plan 2016-2020.
162
Van Eerd, Laura. Cornell Soil Health Assessment as a possible soil quality standard for Ontario. Project report submitted to Farm
and Food Care Ontario, Jan 31, 2015.
163
Australia already has a well-developed program of carbon credits and offsets. See this article for a description and discussion of the
4/1000 initiative: Koch, Andrea et al. Global Policy Journal. 4/1000 initiative– Soil Carbon to Mitigate Climate Change.
164
No-Till Farmer. Carbon Trading Pays for Alberta Farmers.
165
Farm and Dairy. Will it work to pay farmers to sequester carbon? Sept 26, 2016.
166
American Carbon Registry. Reduced Use of Nitrogen Fertilizer on Agricultural Crops. See:
http://americancarbonregistry.org/carbon-accounting/standards-methodologies/emissions-reductions-through-reduced-use-ofnitrogen-fertilizer-on-agricultural-crops ; Climate Action Reserve. Nitrogen Management Project Protocol Vol. 1.1 See:
http://www.climateactionreserve.org/how/protocols/nitrogen-management/ ; and, Verified Carbon Standard. “Quantifying N2O
Emissions Reductions in Agricultural Crops through Nitrogen Fertilizer rate reduction – Vol. 1.1”. – see http://database.v-cs.org/methodologies/quantifying-n2o-emissions-reductions-agricultural-crops-through-nitrogen-fertilizer .
167
American Carbon Registry. “Changes in Fertilizer Management” See: http://americancarbonregistry.org/carbonaccounting/standards-methodologies/emissions-reductions-through-changes-in-fertilizer-management .
168
For a good discussion of the potential of incentives, see; Lovell, Angela. Counting the full value of farming. Country Guide, Oct. 14,
2016.
169
For a good analysis of what needs to be done to implement the 4/1000 Initiative, see: Chambers, Lal, and Paustian. Journal of Soil
and Water Conservation. May/June, 2016. Soil carbon sequestration potential of US croplands and grasslands: Implementing the 4
per Thousand Initiative, pp. 68A-74A.
PUTTING SOIL HEALTH FIRST
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